Robbie the Rabbit's favorite food is definitely healthy. Maybe it's one of your child's favorites, too. To find out what it is, kids add or subtract the numbers in each problem. Each sum or difference corresponds to a letter, and some of those letters belong in the mystery word on the bottom of the page. After solving all the problems, kids fill in the letters to reveal the mystery word. This worksheet offers practice with solving addition and subtraction problems with one- and two-digit numbers; horizontal and vertical addition and subtraction; and writing whole numbers up to 10.