The research reported dealt with the ability of first, second, and third grade students to understand the topological concepts of solids, sheets, lines, networks, and of order and betweenness. The concepts were presented through the use of manipulative materials. The instruction was conducted by the regular teachers for a period of three weeks after which test items in workbooks completed by the students, were used for obtaining data. The achievement of each class on each item was tabulated, and differences in performance are discussed. The author concludes that the material presented seems suitable for children in the age range studied. (JG)