HOW do you fit both large and small stones into a glass jar? If you first fill the jar with the small stones, there may not be enough space left to put in the large ones. The large stones must be put in first and the small stones then poured over them, filling in the gaps.

This lesson was displayed on a video screen at the National Department of Educations Center of Education & Training in Sawangan, Depok last Wednesday. The audience comprised 30