Twelve boys collected 16 aluminum cans each. Fifteen girls collected 14 aluminum cans each. How many more cans did the girls collect than boys?
The girls collected 18 more cans.
you need to find the total cans collected by boys and girls. To do this you multiply 16 and 12 for the guys cans and 15 and 14 for the girls cans.
Once you have your products you subtract them and you'll get 18 :)