1.At 70 cents per 100 pounds, what will be the amount of duty on an invoice of 3622 steel rails, each rail being 27 feet long and weighing 60 pounds to the yard?2.A man had property valued at $6500. What will be his taxes at the rate of $10.80 per $1000?3.Multiply seventy thousand fourteen hundred-thousandths by one hundred nine millionths, and divide the product by five hundred forty-five.4.What number multiplied by 43¾ will produce 2655⁄8?5.What decimal of a bushel is 3 quarts?6.A man sells5⁄8of an acre of land for $93.75. What would be the value of his farm of 150¾ acres at the same rate?7.A coal dealer buys 375 tons coal at $4.25 per ton of 2240 pounds. He sells it at $4.50 per ton of 2000 pounds. What is his profit?8.Bought 60 yards of cloth at the rate of 2 yards for $5, and 80 yards more at the rate of 4 yards for $9. I immediately sold the whole of it at the rate of 5 yards for $12. How much did I gain?9.A man purchased 40 bushels of apples at $1.50 per bushel. Twenty-five hundredths of them were damaged, and he sold them at 20 cents per peck. He sold the remainder at 50 cents per peck. How much did he gain or lose?10.If oranges are 37½ cents per dozen, how many boxes, each containing 480, can be bought for $60?11.A man can do a piece of work in 18¾ days. What part of it can he do in 62⁄3days?12.How old to-day is a boy that was born Oct. 29, 1896? [Walsh, '06, Part I, p. 165.]
1.At 70 cents per 100 pounds, what will be the amount of duty on an invoice of 3622 steel rails, each rail being 27 feet long and weighing 60 pounds to the yard?
2.A man had property valued at $6500. What will be his taxes at the rate of $10.80 per $1000?
3.Multiply seventy thousand fourteen hundred-thousandths by one hundred nine millionths, and divide the product by five hundred forty-five.
4.What number multiplied by 43¾ will produce 2655⁄8?
5.What decimal of a bushel is 3 quarts?
6.A man sells5⁄8of an acre of land for $93.75. What would be the value of his farm of 150¾ acres at the same rate?
7.A coal dealer buys 375 tons coal at $4.25 per ton of 2240 pounds. He sells it at $4.50 per ton of 2000 pounds. What is his profit?
8.Bought 60 yards of cloth at the rate of 2 yards for $5, and 80 yards more at the rate of 4 yards for $9. I immediately sold the whole of it at the rate of 5 yards for $12. How much did I gain?
9.A man purchased 40 bushels of apples at $1.50 per bushel. Twenty-five hundredths of them were damaged, and he sold them at 20 cents per peck. He sold the remainder at 50 cents per peck. How much did he gain or lose?
10.If oranges are 37½ cents per dozen, how many boxes, each containing 480, can be bought for $60?
11.A man can do a piece of work in 18¾ days. What part of it can he do in 62⁄3days?
12.How old to-day is a boy that was born Oct. 29, 1896? [Walsh, '06, Part I, p. 165.]
As a result, teachers and textbook writers have come to think of the functions of solving arithmetical problems as identical with the function of solving the described problems which they give in school in books, examination papers, and the like. If they do not think explicitly that this is so, they still act in training and in testing pupils as if it were so.
It is not. Problems should be solved in school to the end that pupils may solve the problems which life offers. To know what change one should receive after a given real purchase, to keep one's accounts accurately, to adapt a recipe for six so as to make enough of the article for four persons, to estimate the amount of seed required for a plot of a given size from the statement of the amount required per acre, to make with surety the applications that the household, small stores, and ordinary trades require—such is the ability that the elementary school should develop.Other things being equal, the school should set problems in arithmetic which life then and later will set, should favor the situations which life itself offers and the responses which life itself demands.
Other things are not always equal. The same amount of time and effort will often be more productive toward the final end if directed during school to 'made-up' problems. The keeping of personal financial accounts as a school exercise is usually impracticable, partly because some of the children have no earnings or allowance—no accounts to keep, and partly because the task of supervising work when each child has a different problem is too great for the teacher. The use of real household and shop problems will be easy only when the school program includes the household arts and industrial education, and when these subjects themselves are taught so as to improve the functions used by real life. Very often the most efficient course is to make sure that arithmetical procedures are applied to the real and personally initiated problems which they fit, by having a certain number of such problems arise and be solved; then to make sure that the similarity between these real problems and certain described problems of the textbook or teacher's giving is appreciated; and then to give the needed drill work with described problems. In many cases the school practice is fairly well justified in assuming that solving described problems will prepare the pupil to solve the corresponding real problems actually much better than the same amount of time spent on the real problems themselves.
All this is true, yet the general principle remains that, other things being equal, the school should favor real situations, should present issues as life will present them.
Where other things make the use of verbally describedproblems of the ordinary type desirable, these should be chosen so as to give a maximum of preparation for the real applications of arithmetic in life. We should not, for example, carelessly use any problem that comes to mind in applying a certain principle, but should stop to consider just what the situations of life really require and show clearly the application of that principle. For example, contrast these two problems applying cancellation:—
A. A man sold 24 lambs at $18 apiece on each of six days, and bought 8 pounds of metal with the proceeds. How much did he pay per ounce for the metal?B. How tall must a rectangular tank 16" long by 8" wide be to hold as much as a rectangular tank 24" by 18" by 6"?
A. A man sold 24 lambs at $18 apiece on each of six days, and bought 8 pounds of metal with the proceeds. How much did he pay per ounce for the metal?
B. How tall must a rectangular tank 16" long by 8" wide be to hold as much as a rectangular tank 24" by 18" by 6"?
The first problem not only presents a situation that would rarely or never occur, but also takes a way to find the answer that would not, in that situation, be taken since the price set by another would determine the amount.
Much thought and ingenuity should in the future be expended in eliminating problems whose solution does not improve the real function to be improved by applied arithmetic, or improves it at too great cost, and in devising problems which prepare directly for life's demands and still can fit into a curriculum that can be administered by one teacher in charge of thirty or forty pupils, under the limitations of school life.
The following illustrations will to some extent show concretely what the ability to apply the knowledge and power represented by abstract or pure arithmetic—the so-called fundamentals—in solving problems should mean and what it should not mean.
Keeping the scores and deciding which side beat and by how much in appropriate classroom games, spelling matches, and the like.
Computing costs, making and inspecting change, taking inventories, and the like with a real or play store.
Mapping the school garden, dividing it into allotments, planning for the purchase of seeds, and the like.
Measuring one's own achievement and progress in tests of word-knowledge, spelling, addition, subtraction, speed of writing, and the like. Measuring the rate of improvement per hour of practice or per week of school life, and the like.
Estimating costs of food cooked in the school kitchen, articles made in the school shops, and the like.
Computing the cost of telegrams, postage, expressage, for a real message or package, from the published tariffs.
Computing costs from mail order catalogues and the like.
The samples given here all concern the subtraction of fractions. Samples concerning any other arithmetical principle may be found in the appropriate pages of any text which contains problem-material selected with consideration of life's needs.
1.Dora is making jelly. The recipe calls for 24 cups of sugar and she has only 21½. She has no time to go to the store so she has to borrow the sugar from a neighbor. How much must she get?Subtract
1.Dora is making jelly. The recipe calls for 24 cups of sugar and she has only 21½. She has no time to go to the store so she has to borrow the sugar from a neighbor. How much must she get?
Subtract
24Think "½ and ½ = 1." Write ½.21½Think "2 and 2 = 4." Write the 2.———2½
2.A box full of soap weighs 29½ lb. The empty box weighs 3½ lb. How much does the soap alone weigh?3.On July 1, Mr. Lewis bought a 50-lb. bag of ice-cream salt. On July 15 there were just 11½ lb. left. How much had he used in the two weeks?4.Grace promised to pick 30 qt. blueberries for her mother. So far she has picked 18½ qt. How many more quarts must she pick?
2.A box full of soap weighs 29½ lb. The empty box weighs 3½ lb. How much does the soap alone weigh?
3.On July 1, Mr. Lewis bought a 50-lb. bag of ice-cream salt. On July 15 there were just 11½ lb. left. How much had he used in the two weeks?
4.Grace promised to pick 30 qt. blueberries for her mother. So far she has picked 18½ qt. How many more quarts must she pick?
This table of numbers tells what Nell's baby sister Mary weighed every two months from the time she was born till she was a year old.
This table of numbers tells what Nell's baby sister Mary weighed every two months from the time she was born till she was a year old.
Weight of Mary AdamsWhen born73⁄8lb.2 months old111⁄4lb.4 months old141⁄8lb.6 months old153⁄4lb.8 months old175⁄8lb.10 months old191⁄2lb.12 months old213⁄8lb.
1.How much did the Adams baby gain in the first two months?2.How much did the Adams baby gain in the second two months?3.In the third two months?4.In the fourth two months?5.From the time it was 8 months old till it was 10 months old?6.In the last two months?7.From the time it was born till it was 6 months old?
1.How much did the Adams baby gain in the first two months?
2.How much did the Adams baby gain in the second two months?
3.In the third two months?
4.In the fourth two months?
5.From the time it was 8 months old till it was 10 months old?
6.In the last two months?
7.From the time it was born till it was 6 months old?
1.Helen's exact average for December was 871⁄3. Kate's was 841⁄2. How much higher was Helen's than Kate's?
1.Helen's exact average for December was 871⁄3. Kate's was 841⁄2. How much higher was Helen's than Kate's?
871⁄3841⁄2———
How do you think of1⁄2and1⁄3?How do you think of 12⁄6?How do you change the 4?2.Find the exact average for each girl in the following list. Write the answers clearly so that you can see them easily. You will use them in solving problems 3, 4, 5, 6, 7, and 8.
How do you think of1⁄2and1⁄3?
How do you think of 12⁄6?
How do you change the 4?
2.Find the exact average for each girl in the following list. Write the answers clearly so that you can see them easily. You will use them in solving problems 3, 4, 5, 6, 7, and 8.
AliceDoraEmmaGraceLouiseMaryNellRebeccaReading9187838179777673Language8878827973787375Arithmetic8985797584878980Spelling9079758082916881Geography9187837578857379Writing9088757293929578
3.Which girl had the highest average?4.How much higher was her average than the next highest?5.How much difference was there between the highest and the lowest girl?6.Was Emma's average higher or lower than Louise's? How much?7.How much difference was there between Alice's average and Dora's?8.How much difference was there between Mary's average and Nell's?9.Write five other problems about these averages, and solve each of them.
3.Which girl had the highest average?
4.How much higher was her average than the next highest?
5.How much difference was there between the highest and the lowest girl?
6.Was Emma's average higher or lower than Louise's? How much?
7.How much difference was there between Alice's average and Dora's?
8.How much difference was there between Mary's average and Nell's?
9.Write five other problems about these averages, and solve each of them.
Will has XXI marbles, XII jackstones, XXXVI pieces of string. How many things had he?George's kite rose CDXXXV feet and Tom's went LXIII feet higher. How high did Tom's kite rise?If from DCIV we take CCIV the result will be a number IV times as large as the number of dollars Mr. Dane paid for his horse. How much did he pay for his horse?Hannah has5⁄8of a dollar, Susie7⁄25, Nellie3⁄4, Norah13⁄16. How much money have they all together?A man saves 317⁄80dollars a week. How much does he save in a year?A tree fell and was broken into 4 pieces, 131⁄6feet, 103⁄7feet, 81⁄2feet, and 716⁄21feet long. How tall was the tree?Annie's father gave her 20 apples to divide among her friends. She gave each one 22⁄9apples apiece. How many playmates had she?John had 172⁄5apples. He divided his whole apples into fifths. How many pieces had he in all?A landlady has 33⁄7pies to be divided among her 8 boarders. How much will each boarder receive?There are twenty columns of spelling words in Mary's lesson and 16 words in each column. How many words are in her lesson?There are 9 nuts in a pint. How many pints in a pile of 5,888,673 nuts?The Adams school contains eight rooms; each room contains 48 pupils; if each pupil has eight cents, how much have they together?A pile of wood in the form of a cube contains 15½ cords. What are the dimensions to the nearest inch?A man 6 ft. high weighs 175 lb. How tall is his wife who is of similar build, and weighs 125 lb.?A stick of timber is in the shape of the frustum of a square pyramid, the lower base being 22 in. square and the upper 14 in. square. How many cubic feet in the log, if it is 22 ft. long?Mr. Ames, being asked his age, replied: "If you cube one half of my age and add 41,472 to the result, the sum will be one half the cube of my age. How old am I?"
Will has XXI marbles, XII jackstones, XXXVI pieces of string. How many things had he?
George's kite rose CDXXXV feet and Tom's went LXIII feet higher. How high did Tom's kite rise?
If from DCIV we take CCIV the result will be a number IV times as large as the number of dollars Mr. Dane paid for his horse. How much did he pay for his horse?
Hannah has5⁄8of a dollar, Susie7⁄25, Nellie3⁄4, Norah13⁄16. How much money have they all together?
A man saves 317⁄80dollars a week. How much does he save in a year?
A tree fell and was broken into 4 pieces, 131⁄6feet, 103⁄7feet, 81⁄2feet, and 716⁄21feet long. How tall was the tree?
Annie's father gave her 20 apples to divide among her friends. She gave each one 22⁄9apples apiece. How many playmates had she?
John had 172⁄5apples. He divided his whole apples into fifths. How many pieces had he in all?
A landlady has 33⁄7pies to be divided among her 8 boarders. How much will each boarder receive?
There are twenty columns of spelling words in Mary's lesson and 16 words in each column. How many words are in her lesson?
There are 9 nuts in a pint. How many pints in a pile of 5,888,673 nuts?
The Adams school contains eight rooms; each room contains 48 pupils; if each pupil has eight cents, how much have they together?
A pile of wood in the form of a cube contains 15½ cords. What are the dimensions to the nearest inch?
A man 6 ft. high weighs 175 lb. How tall is his wife who is of similar build, and weighs 125 lb.?
A stick of timber is in the shape of the frustum of a square pyramid, the lower base being 22 in. square and the upper 14 in. square. How many cubic feet in the log, if it is 22 ft. long?
Mr. Ames, being asked his age, replied: "If you cube one half of my age and add 41,472 to the result, the sum will be one half the cube of my age. How old am I?"
These samples, just given, of the kind of problem-solving that should not be emphasized in school training refer in some cases to books of forty years back, but the following represent the results of a collection made in 1910 from books then in excellent repute. It required only about an hour to collect them; and I am confident that a thousand such problems describing situations that the pupil will never encounter in real life, or putting questions that he will never be asked in real life, could easily be found in any ten textbooks of the decade from 1900 to 1910.
If there are 250 kernels of corn on one ear, how many are there on 24 ears of corn the same size?Maud is four times as old as her sister, who is 4 years old. What is the sum of their ages?If the first century began with the year 1, with what year does it end?Every spider has 8 compound eyes. How many eyes have 21 spiders?A nail 4 inches long is driven through a board so that it projects 1.695 inches on one side and 1.428 on the other. How thick is the board?Find the perimeter of an envelope 5 in. by 3¼ in.How many minutes in5⁄9of9⁄4of an hour?Mrs. Knox is3⁄4as old as Mr. Knox, who is 48 years old. Their son Edward is4⁄9as old as his mother. How old is Edward?Suppose a pie to be exactly round and 10½ miles in diameter. If it were cut into 6 equal pieces, how long would the curved edge of each piece be?81⁄3% of a class of 36 boys were absent on a rainy day. 331⁄3% of those present went out of the room to the school yard. How many were left in the room?Just after a ton of hay was weighed in market, a horse ate one pound of it. What was the ratio of what he ate to what was left?If a fan having 15 rays opens out so that the outer rays form a straight line, how many degrees are there between any two adjacent rays?One half of the distance between St. Louis and New Orleans is 280 miles more than1⁄10of the distance; what is the distance between these places?If the pressure of the atmosphere is 14.7 lb. per square inch what is the pressure on the top of a table 1¼ yd. long and2⁄3yd. wide?13⁄28of the total acreage of barley in 1900 was 100,000 acres; what was the total acreage?What is the least number of bananas that a mother can exactly divide between her 2 sons, or among her 4 daughters, or among all her children?If Alice were two years older than four times her actual age she would be as old as her aunt, who is 38 years old. How old is Alice?Three men walk around a circular island, the circumference of which is 360 miles. A walks 15 miles a day, B 18 miles a day, and C 24 miles a day. If they start together and walk in the same direction, how many days will elapse before they will be together again?
If there are 250 kernels of corn on one ear, how many are there on 24 ears of corn the same size?
Maud is four times as old as her sister, who is 4 years old. What is the sum of their ages?
If the first century began with the year 1, with what year does it end?
Every spider has 8 compound eyes. How many eyes have 21 spiders?
A nail 4 inches long is driven through a board so that it projects 1.695 inches on one side and 1.428 on the other. How thick is the board?
Find the perimeter of an envelope 5 in. by 3¼ in.
How many minutes in5⁄9of9⁄4of an hour?
Mrs. Knox is3⁄4as old as Mr. Knox, who is 48 years old. Their son Edward is4⁄9as old as his mother. How old is Edward?
Suppose a pie to be exactly round and 10½ miles in diameter. If it were cut into 6 equal pieces, how long would the curved edge of each piece be?
81⁄3% of a class of 36 boys were absent on a rainy day. 331⁄3% of those present went out of the room to the school yard. How many were left in the room?
Just after a ton of hay was weighed in market, a horse ate one pound of it. What was the ratio of what he ate to what was left?
If a fan having 15 rays opens out so that the outer rays form a straight line, how many degrees are there between any two adjacent rays?
One half of the distance between St. Louis and New Orleans is 280 miles more than1⁄10of the distance; what is the distance between these places?
If the pressure of the atmosphere is 14.7 lb. per square inch what is the pressure on the top of a table 1¼ yd. long and2⁄3yd. wide?
13⁄28of the total acreage of barley in 1900 was 100,000 acres; what was the total acreage?
What is the least number of bananas that a mother can exactly divide between her 2 sons, or among her 4 daughters, or among all her children?
If Alice were two years older than four times her actual age she would be as old as her aunt, who is 38 years old. How old is Alice?
Three men walk around a circular island, the circumference of which is 360 miles. A walks 15 miles a day, B 18 miles a day, and C 24 miles a day. If they start together and walk in the same direction, how many days will elapse before they will be together again?
With only thirty or forty dollars a year to spend on a pupil's education, of which perhaps eight dollars are spenton improving his arithmetical abilities, the immediate guidance of his responses to real situations and personally initiated problems has to be supplemented largely by guidance of his responses to problems described in words, diagrams, pictures, and the like. Of these latter, words will be used most often. As a consequence the understanding of the words used in these descriptions becomes a part of the ability required in arithmetic. Such word knowledge is also required in so far as the problems to be solved in real life are at times described, as in advertisements, business letters, and the like.
This is recognized by everybody in the case of words likeremainder,profit,loss,gain,interest,cubic capacity,gross,net, anddiscount, but holds equally oflet,suppose,balance,average,total,borrowed,retained, and many such semi-technical words, and may hold also of hundreds of other words unless the textbook and teacher are careful to use only words and sentence structures which daily life and the class work in English have made well known to the pupils. To apply arithmetic to a problem a pupil must understand what the problem is; problem-solving depends on problem-reading. In actual school practice training in problem-reading will be less and less necessary as we get rid of problems to be solved simply for the sake of solving them, unnecessarily unreal problems, and clumsy descriptions, but it will remain to some extent as an important joint task for the 'arithmetic' and 'reading' of the elementary school.
The last respect in which the nature of arithmetical abilities requires definition concerns arithmetical reasoning. An adequate treatment of the reasoning that may be expected of pupils in the elementary school and of the mostefficient ways to encourage and improve it cannot be given until we have studied the formation of habits. For reasoning is essentially the organization and control of habits of thought. Certain matters may, however, be decided here. The first concerns the use of computation and problems merely for discipline,—that is, the emphasis on training in reasoning regardless of whether the problem is otherwise worth reasoning about. It used to be thought that the mind was a set of faculties or abilities or powers which grew strong and competent by being exercised in a certain way, no matter on what they were exercised. Problems that could not occur in life, and were entirely devoid of any worthy interest, save the intellectual interest in solving them, were supposed to be nearly or quite as useful in training the mind to reason as the genuine problems of the home, shop, or trade. Anything that gave the mind a chance to reason would do; and pupils labored to find when the minute hand and hour hand would be together, or how many sheep a shepherd had if half of what he had plus ten was one third of twice what he had!
We now know that the training depends largely on the particular data used, so that efficient discipline in reasoning requires that the pupil reason about matters of real importance. There is no magic essence or faculty of reasoning that works in general and irrespective of the particular facts and relations reasoned about. So we should try to find problems which not only stimulate the pupil to reason, but also direct his reasoning in useful channels and reward it by results that are of real significance. We should replace the purely disciplinary problems by problems that are also valuable as special training for important particular situations of life. Reasoning sought for reasoning's sake alone is too wasteful an expenditure of time and is also likely to be inferior as reasoning.
The second matter concerns the relative merits of 'catch' problems, where the pupil has to go against some customary habit of thinking, and what we may call 'routine' problems, where the regular ways of thinking that have served him in the past will, except for some blunder, guide him rightly.
Consider, for example, these four problems:
1."A man bought ten dozen eggs for $2.50 and sold them for 30 cents a dozen. How many cents did he lose?"2."I went into Smith's store at 9A.M.and remained until 10A.M.I bought six yards of gingham at 40 cents a yard and three yards of muslin at 20 cents a yard and gave a $5.00 bill. How long was I in the store?"3."What must you divide 48 by to get half of twice 6?"4."What must you add to 19 to get 30?"
1."A man bought ten dozen eggs for $2.50 and sold them for 30 cents a dozen. How many cents did he lose?"
2."I went into Smith's store at 9A.M.and remained until 10A.M.I bought six yards of gingham at 40 cents a yard and three yards of muslin at 20 cents a yard and gave a $5.00 bill. How long was I in the store?"
3."What must you divide 48 by to get half of twice 6?"
4."What must you add to 19 to get 30?"
The 'catch' problem is now in disrepute, the wise teacher feeling by a sort of intuition that to willfully require a pupil to reason to a result sharply contrary to that to which previous habits lead him is risky. The four illustrations just given show, however, that mere 'catchiness' or 'contra-previous-habit-ness' in a problem is not enough to condemn it. The fourth problem is a catch problem, but so useful a one that it has been adopted in many modern books as a routine drill! The first problem, on the contrary, all, save those who demand no higher criterion for a problem than that it make the pupil 'think,' would reject. It demands the reversal of fixed habitsto no valid purpose; for in life the question in such case would never (or almost never) be 'How many cents did he lose?' but 'What was the result?' or simply 'What of it?' This problem weakens without excuse the child's confidence in the training he has had. Problems like (2) are given by teachers of excellent reputation, but probably do more harm than good. If a pupil should interrupt his teacher during the recitation in arithmetic bysaying, "I got up at 7 o'clock to multiply 9 by 2¾ and got 24¾ for my answer; was that the right time to get up?" the teacher would not thank fortune for the stimulus to thought but would think the child a fool. Such catch questions may be fairly useful as an object lesson on the value of search for the essential element in a situation if a great variety of them are given one after another with routine problems intermixed and with warning of the general nature of the exercise at the beginning. Even so, it should be remembered that reasoning should be chiefly a force organizing habits, not opposing them; and also that there are enough bad habits to be opposed to give all necessary training. Fabricated puzzle situations wherein a peculiar hidden element of the situation makes the good habits called up by the situation misleading are useful therefore rather as a relief and amusing variation in arithmetical work than as stimuli to thought.
Problems like the third quoted above we might call puzzling rather than 'catch' problems. They have value as drills in analysis of a situation into its elements that will amuse the gifted children, and as tests of certain abilities. They also require that of many confusing habits, the right one be chosen, rather than that ordinary habits be set aside by some hidden element in the situation. Not enough is known about their effect to enable us to decide whether or not the elementary school should include special facility with them as one of the arithmetical functions that it specially trains.
The fourth 'catch' quoted above, which all would admit is a good problem, is good because it opposes a good habit for the sake of another good habit, forces the analysis of an element whose analysis life very much requires, and does it with no obvious waste. It is not safe to leave a child with the one habit of responding to 'add, 19, 30' by 49, for inlife the 'have 19, must get .... to have 30' situation is very frequent and important.
On the whole, the ordinary problems which ordinary life proffers seem to be the sort that should be reasoned out, though the elementary school may include the less noxious forms of pure mental gymnastics for those pupils who like them.
These discussions of the meanings of numbers, the linguistic demands of arithmetic, the distinction between scholastic and real applications of arithmetic, and the possible restrictions of training in reasoning,—may serve as illustrations of the significance of the question, "What are the functions that the elementary school tries to improve in its teaching of arithmetic?" Other matters might well be considered in this connection, but the main outline of the work of the elementary school is now fairly clear. The arithmetical functions or abilities which it seeks to improve are, we may say:—
(1) Working knowledge of the meanings of numbers as names for certain sized collections, for certain relative magnitudes, the magnitude of unity being known, and for certain centers or nuclei of relations to other numbers.
(2) Working knowledge of the system of decimal notation.
(3) Working knowledge of the meanings of addition, subtraction, multiplication, and division.
(4) Working knowledge of the nature and relations of certain common measures.
(5) Working ability to add, subtract, multiply, and divide with integers, common and decimal fractions, and denominate numbers, all being real positive numbers.
(6) Working knowledge of words, symbols, diagrams, andthe like as required by life's simpler arithmetical demands or by economical preparation therefor.
(7) The ability to apply all the above as required by life's simpler arithmetical demands or by economical preparation therefor, including (7a) certain specific abilities to solve problems concerning areas of rectangles, volumes of rectangular solids, percents, interest, and certain other common occurrences in household, factory, and business life.
The phrase 'life's simpler arithmetical demands' is necessarily left vague. Just what use is being made of arithmetic in this country in 1920 by each person therein, we know only very roughly. What may be called a 'sociology' of arithmetic is very much needed to investigate this matter. For rare or difficult demands the elementary school should not prepare; there are too many other desirable abilities that it should improve.A most interesting beginning at such an inventory of the actual uses of arithmetic has been made by Wilson ['19] and Mitchell.[2]Although their studies need to be much extended and checked by other methods of inquiry, two main facts seem fairly certain.First, the great majority of people in the great majority of their doings use only very elementary arithmetical processes. In 1737 cases of addition reported by Wilson, seven eighths were of five numbers or less. Over half of the multipliers reported were one-figure numbers. Over 95 per cent of the fractions operated with were included in this list:1⁄21⁄43⁄41⁄32⁄31⁄83⁄81⁄52⁄54⁄5. Three fourths of all the cases reported were simple one-step computations with integers or United States money.Second, they often use these very elementary processes, not because such are the quickest and most convenient, but because they have lost, or maybe never had, mastery of the more advanced processes which would do the work better. The 5 and 10 cent stores, the counter with "Anything on this counter for 25¢," and the arrangements for payments on the installment plan are familiar instances of human avoidance of arithmetic. Wilson found very slight use of decimals; and Mitchell found men computing with49ths as common fractions when the use of decimals would have been more efficient. If given 120 seconds to do a test like that shown below, leading lawyers, physicians, manufacturers, and business men and their wives will, according to my experience, get only about half the work right. Many women, finding on their meat bill "73⁄8lb. roast beef $2.36," will spend time and money to telephone the butcher asking how much roast beef was per pound, because they have no sure power in dividing by a mixed number.
The phrase 'life's simpler arithmetical demands' is necessarily left vague. Just what use is being made of arithmetic in this country in 1920 by each person therein, we know only very roughly. What may be called a 'sociology' of arithmetic is very much needed to investigate this matter. For rare or difficult demands the elementary school should not prepare; there are too many other desirable abilities that it should improve.
A most interesting beginning at such an inventory of the actual uses of arithmetic has been made by Wilson ['19] and Mitchell.[2]Although their studies need to be much extended and checked by other methods of inquiry, two main facts seem fairly certain.
First, the great majority of people in the great majority of their doings use only very elementary arithmetical processes. In 1737 cases of addition reported by Wilson, seven eighths were of five numbers or less. Over half of the multipliers reported were one-figure numbers. Over 95 per cent of the fractions operated with were included in this list:1⁄21⁄43⁄41⁄32⁄31⁄83⁄81⁄52⁄54⁄5. Three fourths of all the cases reported were simple one-step computations with integers or United States money.
Second, they often use these very elementary processes, not because such are the quickest and most convenient, but because they have lost, or maybe never had, mastery of the more advanced processes which would do the work better. The 5 and 10 cent stores, the counter with "Anything on this counter for 25¢," and the arrangements for payments on the installment plan are familiar instances of human avoidance of arithmetic. Wilson found very slight use of decimals; and Mitchell found men computing with49ths as common fractions when the use of decimals would have been more efficient. If given 120 seconds to do a test like that shown below, leading lawyers, physicians, manufacturers, and business men and their wives will, according to my experience, get only about half the work right. Many women, finding on their meat bill "73⁄8lb. roast beef $2.36," will spend time and money to telephone the butcher asking how much roast beef was per pound, because they have no sure power in dividing by a mixed number.
TestPerform the operations indicated. Express all fractions in answers in lowest terms.Add:3⁄4+1⁄6+ .254 yr. 6 mo.1 yr. 2 mo.6 yr. 9 mo.3 yr. 6 mo.4 yr. 5 mo.Subtract:8.6 − 6.050077⁄8−2⁄3= 57⁄16− 23⁄16=Multiply:7 × 8 × 4½ =29 ft.6 in.8Divide:4½ ÷ 7 =It seems probable that the school training in arithmetic of the past has not given enough attention to perfecting the more elementary abilities. And we shall later find further evidence of this. On the other hand, the fact that people in general do not at present use a process may not mean that they ought not to use it.Life's simpler arithmetical demands certainly do not include matters like the rules for finding cube root or true discount, which no sensible person uses. They should not include matters like computing the lateral surface or volume of pyramids and cones, or knowing the customs of plasterers and paper hangers, which are used only by highly specialized trades. They should not include matters like interest on call loans, usury, exact interest, andthe rediscounting of notes, which concern only brokers, bank clerks, and rich men. They should not include the technique of customs which are vanishing from efficient practice, such as simple interest on amount for times longer than a year, days of grace, or extremes and means in proportions. They should not include any elaborate practice with very large numbers, or decimals beyond thousandths, or the addition and subtraction of fractions which not one person in a hundred has to add or subtract oftener than once a year.When we have an adequate sociology of arithmetic, stating accurately just who should use each arithmetical ability and how often, we shall be able to define the task of the elementary school in this respect. For the present, we may proceed by common sense, guided by two limiting rules. The first is,—"It is no more desirable for the elementary school to teach all the facts of arithmetic than to teach all the words in the English language, or all the topography of the globe, or all the details of human physiology." The second is,—"It is not desirable to eliminate any element of arithmetical training until you have something better to put in its place."
Test
Perform the operations indicated. Express all fractions in answers in lowest terms.
Add:3⁄4+1⁄6+ .254 yr. 6 mo.1 yr. 2 mo.6 yr. 9 mo.3 yr. 6 mo.4 yr. 5 mo.Subtract:8.6 − 6.050077⁄8−2⁄3= 57⁄16− 23⁄16=Multiply:7 × 8 × 4½ =29 ft.6 in.8Divide:4½ ÷ 7 =
Add:
Subtract:
Multiply:
Divide:
4½ ÷ 7 =
It seems probable that the school training in arithmetic of the past has not given enough attention to perfecting the more elementary abilities. And we shall later find further evidence of this. On the other hand, the fact that people in general do not at present use a process may not mean that they ought not to use it.
Life's simpler arithmetical demands certainly do not include matters like the rules for finding cube root or true discount, which no sensible person uses. They should not include matters like computing the lateral surface or volume of pyramids and cones, or knowing the customs of plasterers and paper hangers, which are used only by highly specialized trades. They should not include matters like interest on call loans, usury, exact interest, andthe rediscounting of notes, which concern only brokers, bank clerks, and rich men. They should not include the technique of customs which are vanishing from efficient practice, such as simple interest on amount for times longer than a year, days of grace, or extremes and means in proportions. They should not include any elaborate practice with very large numbers, or decimals beyond thousandths, or the addition and subtraction of fractions which not one person in a hundred has to add or subtract oftener than once a year.
When we have an adequate sociology of arithmetic, stating accurately just who should use each arithmetical ability and how often, we shall be able to define the task of the elementary school in this respect. For the present, we may proceed by common sense, guided by two limiting rules. The first is,—"It is no more desirable for the elementary school to teach all the facts of arithmetic than to teach all the words in the English language, or all the topography of the globe, or all the details of human physiology." The second is,—"It is not desirable to eliminate any element of arithmetical training until you have something better to put in its place."
One of the best ways to clear up notions of what the functions are which schools should develop and improve is to get measures of them. If any given knowledge or skill or power or ideal exists, it exists in some amount. A series of amounts of it, varying from less to more, defines the ability itself in a way that no general verbal description can do. Thus, a series of weights, 1 lb., 2 lb., 3 lb., 4 lb., etc., helps to tell us what we mean by weight. By finding a series of words likeonly,smoke,another,pretty,answer,tailor,circus,telephone,saucy, andbeginning, which are spelled correctly by known and decreasing percentages of children of the same age, or of the same school grade, we know better what we mean by 'spelling-difficulty.' Indeed, until we can measure the efficiency and improvement of a function, we are likely to be vague and loose in our ideas of what the function is.
Consider first, as a sample, the measurement of ability to add integers.
The following were the examples used in the measurements made by Stone ['08]:
59646954288722375947948405275678663543045672606458585041984944715438977499—————————
The scoring was as follows: Credit of 1 for each column added correctly. Stone combined measures of other abilities with this in a total score for amount done correctly in 12 minutes. Stone also scored the correctness of the additions in certain work in multiplication.
Courtis uses a sheet of twenty-four tasks or 'examples,' each consisting of the addition of nine three-place numbers as shown below. Eight minutes is allowed. He scores the amount done by the number of examples, and also scores the number of examples done correctly, but does not suggest any combination of these two into a general-efficiency score.
927379756837924110854965344———
The author long ago proposed that pupils be measured also with series likeatogshown below, in which the difficulty increases step by step.
a.322322122312455142333222————————
b.213212243434221223125231331223132425151432234361————————
c.223435328322333132331132138455252243364————————
d.3020102210205212205040433046224017241340233044————————
e.452012122010203034041120201030204123722024023401110302020101120223025————————
f.1999142192494139141312131391417231315153412252629181925281839————————