Sonobe Cube

Exploring volume is one of the most interesting and useful exercises in mathematics. We measure volume in cubic units so it is only logical to teach the children how to build cubes.

In the mid 1960s, Mitsunobu Sonobe from Japan, created the design now know as the Sonobe Cube. The children were taught how to create six congruent (identical) units from a square piece of paper. It is best to use two each of three different colored paper. Please see the attached pdf for folding instructions.

The learning objectives are:

1. Cutting paper by creasing at desired fold, licking the edge to weaken the integrity of the paper and cutting with precision.
2. Creating a square from a non-square rectangle.
3. Folding paper with precision.
4. Creating isosceles right triangles, parallelograms and squares.
5. Following a set of complex instructions to interlock all six pieces to form a cube. The most important term is perpendicular as they are required to hold each piece at a ninety degree angle in order to insert one tab into the other piece.