A set of eight wooden cubes and prisms in a wooden box painted red, blue and black. The specially attached wooden hinges allow the four sides of the box to open out flat permitting unhindered access. The control chart is screen printed on the lid of the box making it convenient and an effective means for use. This material is a concrete representation of the binomial equation (a+b)2 and helps to develop the child's perception of differences in proportion in 3 dimensions and to encourage the perception of a mathematical pattern.