Challenge Level

__ 5, __6 or __ 4, __ 5

__ 5 $\times$ __ 6 = __ 0 , __ 4 $\times$ __ 5 = __ 0 (multiples of 10)

__ 0 $\times$ __ 0 = __ 0 0 (the square of a multiple of 10 is a multiple of 100)

You can find more short problems, arranged by curriculum topic, in our short problems collection.