The material consists of wooden squares and cubes with the basic numbers from 1 to 9. The child can use them to bring a smaller cube, for example the five-cube, to the mass of the eight-cube with the help of five- and three-squares and the three-cube. With advanced practice, this work can be represented and calculated as (5 + 3) 3. This material, like the other materials in this group, offers an excellent opportunity to combine arithmetic, geometry and algebra.