Question

Monica brought some postage stamps.She uses 10 stamps on letters and 5 stamps on postcards.Then her grandmother gives her 20 more stamps. She now has 35 stamps left. How many stamps did Monica originally have?

Answer 1

to find out how many stamps monica originally had, you’d have to do the equation given, “reversed”

equation given: 35 + 20 - 5 - 10

but because we are trying to find how many she originally had left, you’d have to do opposite operations (reverse) in the equation given.

35 - 20 + 5 + 10 = 30

so, this means that monica had 30 stamps originally