About how many books will fit on a shelf that is 40 inches long if each book is 2/3 inches wide?

40 divided by 2/3 inches per book = ?

You need to divide 40 by 2/3.

Your answer will be between 50 and 70 books.

How many 5 inches by 3 and 1/4 inches rectangles will fit into a 12 feet by 4 feet rectangle?