To solve this, we need to add together all of her pens. We have 32 red pens, 25 blue ones, 7 black ones, and 24 green ones. To make things simpler, let's put everything in expanded form to get 30 + 2 + 20 + 5 + 7 + 20 + 4, and if we group the 1 digit numbers and 2 digit numbers, we will get 70 + 18 or 88 pens.
