7. Gavin saved to buy packs of
   baseball cards. His father gives him
   more. If each pack of cards costs
   , how many packs can Gavin buy?

Gavin initially saved , and after his father adds , his total money becomes (because ). If each pack of baseball cards costs , we can find out how many packs he can buy by dividing his total money by the cost of each pack:

So, Gavin can buy 4 packs of baseball cards!

To make this calculation even easier, you can think of it like this: every time he buys a pack, he is spending . With in hand, he can just keep buying packs and counting how many he gets until his money runs out! It’s a fun little budgeting exercise that helps to know how to prioritize your spending.