Much emphasis has been placed on the use of learning devicesin the teaching of mathematics to children. It has been stated that children learn better when they engage in related activities involving the physical manipulation of tangible objects. It is further stated that children also attain a greater level of understanding of concepts when this is the case. There are a number of teaching aids and manipulative objects used in today's schools. From this observation, one may assume that a great deal of emphasis is placed on .the educational value of such devices. However, there is controversy among educators as to whether or not these aids are beneficial to the learning process. Research on the usefulness of manipulative aids is inconclusive. If these aids do foster learning, and this seems to be the important issue, then schools should adopt those teaching methods which allow for pupil manipulation of objects. Should it not be the case, then schools could better allocate funds towards other methods in other areas.This study attempted to determine the relative value of teaching subtraction to children in the elementary grades. One method (A) allowed the subjects to manipulate concrete objects, cuisenaire rods, (Brownell, Arithmetic in Grades I and II) while no such manipulation was presented in the other method (B).