Arithmetic Ability of Mentally Retarded Children: II. Understanding Arithmetic Processes

Abstract

An investigation was undertaken to determine the truth or falsity of the assertion that mentally retarded children of a given mental age are not able to understand as well as normal children of the same mental age the processes which should be employed in the solution of simple exercises in arithmetic. A second aspect of the study endeavored to substantiate or deny the observation of teachers of the mentally retarded that, although the child may indicate that problem should be worked in a given way, he, when asked to solve the problem, proceeds along entirely different arith metical lines from that which he indicated. For example, the mentally re tarded child says that he should subtract to find the correct answer in a certain arithmetic problem, but when he is requested to actually solve the problem he has been observed to use a process other than subtraction. Subjects.?Two groups of fifteen boys each were used in the study: the first, a group of mentally retarded boys from the Wayne County Training School, Northville, Michigan, who comprised the experimental group; the second, a group of boys of normal intelligence from the Adams Elementary School, Birmingham, Michigan, who comprised the control group. The ex perimental subjects had a mean C.A. of 14.29; a mean M.A. of 10.06, and a mean I.Q. of 73-33; the control subjects, a mean C.A. of 9.09, a mean M.A. of 9.96, and a mean I.Q. of 110.4. The mean arithmetic age of the experimental group was 9.73; of the control group 9.84. The T-score between mean mental and mean arithmetic ages of the experimental group is 1.169 at a 5 per cent level of significance; for the control group 1.265 at a 30 per cent level of significance, indicating that basic differences do not exist between mental and arithmetic ages. Significant differences do not exist be tween mental ages of the experimental and control groups (T-score 1.195 at 10 per cent level of significance) or between the arithmetic ages of the two groups subjects (T-score 1.120 at 30 per cent level of significance). The 279