Making Change

PROCEDURE. Ask the following questions in the order here given:--

(a) "_If I were to buy 4 cents worth of candy and should give

the storekeeper 10 cents, how much money would I get back?_"

(b) "_If I bought 13 cents worth and gave the storekeeper

15 cents, how much would I get back?_"

(c) "_If I bought 4 cents worth and gave the storekeeper

25 cents, how much would I get back?_"

Coins are not used, and the subject is not allowed the help of pencil

and paper. If the subject forgets the statement of the problem, it is

permissible to repeat it once, but only once. The response should be

made in ten or fifteen seconds for each problem.

SCORING, The test is passed if _two out of three_ problems are answered

correctly in the allotted time. In case two answers are given to a

problem, we follow the usual rule of counting the second and ignoring

the first.

REMARKS. Problems of this nature, when thoroughly standardized, are

extremely valuable as tests of intelligence. The difficulty of the test,

as we have used it, does not lie in the subtraction of 4 from 10, 12

from 15, etc. Such subtractions, when given as problems in subtraction,

are readily solved by practically all normal 8-year-olds who have

attended school as much as two years. The problems of the test have a

twofold difficulty: (1) The statement of the problem must be

comprehended and held in mind until the solution has been arrived at;

(2) the problem is so stated that the subject must himself select the

fundamental operation which applies. The latter difficulty is somewhat

the greater of the two, addition sometimes being employed instead of


It is just such difficulties as this that prove so perplexing to the

feeble-minded. High-grade defectives, although they require more than

the usual amount of drill and are likely to make occasional errors, are

nevertheless capable of learning to add, subtract, multiply, and divide

fairly well. Their main trouble comes in deciding which of these

operations a given problem calls for. They can master routine, but as

regards initiative, judgment, and power to reason they are little

educable. The psychology and pedagogy of mental deficiency is epitomized

in this statement.

There has been little disagreement as to the proper location of the test

of making change, but various procedures have been employed. Coins have

generally been employed, in which case the subject is actually allowed

to make the change. Most other revisions have also given only a single

problem, usually 4 cents out of 20 cents, or 4 out of 25, or 9 out of

25. It is evident that these are not all of equal difficulty. There is

general agreement, however, that normal children of 9 years should be

able to make simple change.