In 1933 Danish mathematician Piet Hein proposed a three dimensional variation on the tangram puzzle. The puzzle consists of seven polycubes in different configurations that can be put together to form a 3X3 cube.
Hein called his puzzle a Soma Cube, the name purportedly taken from a Sanskrit word for “diversity.” The cube puzzle was popular in Scandinavia, but it wasn’t until Parker Brothers licensed the puzzle in 1969. It remained popular for a decade until it’s popularity was supplanted by another upstart cube puzzle.