Subtraction

5 minus 2 is shown through children queueing for the toilet. If two children go into the toilet how many are still queueing? 5 minus 4 is shown through children jumping into a swimming pool. If 4 jump in how many are left? 5 minus 5 is shown through all 5 children being in the pool and 5 of them leaving, how many will be left in the pool?