Abstract: An educational toy, teaching device and puzzle block combination comprising a plurality of sets of blocks of decreasing dimensions so related one to another as to complete an overall design. Preferably these comprise three sets of cubes color coded so that the combination defined by the cubes may be realized by assembling the cubes in a particular order. To this end there are seven cubes of a given dimension, seven cubes of an intermediate dimension and eight cubes of a smaller dimension. The cubes define three horizontal planes of decreasing size and three vertical planes of a first orientation and of decreasing size and three vertical planes of a second orientation and of decreasing size. The cubes are colored so as to define a pair of matching patterns in each of the nine planes so defined. Each cube, therefore, will be colored on anywhere from three to six of its sides. In the preferred arrangement the colored patterns are circles and all exposed sides of the fully assembled cubes are plain.