These four worksheets are aimed at giving children practice at subtracting multiples of ten from 100. The aim of this is that they learn the answers off by heart, so they no longer have to count on or back. As there only a short number of possibilities it is important for children to know these pairs of numbers which make 100:
10 and 90
20 and 80
30 and 70
40 and 60
50 and 50.
Knowing these makes it much easier to subtract any 2-digit number ‘in your head’.