Frank has an apple tree in his backyard. 5 apples are hanging on the tree and 8 have fallen to the ground. If Frank's dog eats 3 of the apples off of the ground, how many apples are left?
Frank originally had 5 + 8 = <<5+8=13>>13 apples.
After his dog eats 3, there are 13 - 3 = <<13-3=10>>10 apples.
#### 10