How long is a break of 5 minutes? How long are
30 seconds if you are standing on one leg?
Make time visible and let children experience with time.

Sturdy case with 20 sand timers.
4 sand timers of each time: 10 min. (red),
5 min. (green), 3 min. (yellow), 1 min. (blue),
30 sec. (black).