Cara has $25 to buy dry pet food and treats.
If she buys 9 pounds of dog food and a pound of dog food costs $2, you can calculate how many treats she can buy using the following steps:
9 pounds of dog food * $2 = $18
$25 - $18 = $7 left
$7 / $1 = 7 treats
Result: Cara can buy 7 treats.