Worksheet: Addition of Three Numbers within 20

In this worksheet, we will practice using strategies for adding two numbers when adding three numbers whose sum is at most 20.


18 students are wearing colored tops for a game.

There are 7 red tops, some green tops, and 5 blue tops.

Find the addition sentence that matches this story.

  • A
  • B
  • C

How many green tops are there?


Complete the following: 1 + 5 + 4 = .

  • A9
  • B2
  • C0
  • D10


Adel bought 3 bananas, 5 apples, and 6 oranges. How many pieces of fruit did he buy?


The pictures show how many of each type of animal are at a farm.