Answer:
2. We have given the total of 21 children
And 7 children left the library that means 7 have reduced from total
So, the remaining children in the library would be 21-7 = 14
3. Suppose I have a pizza which has 16 slices and i have eaten 12 slices.How many slices have left?
Solution for 3. Total number of slices 16
And 12 have been eaten so, slices i will be left with is 16 -12=4 slices.