Addition within 20 worksheets

Addition within 20 is where children move past counting fingers and start using strategies — making ten, using doubles, counting on. These free printable sheets give that strategy work a happy place to happen.

Kid stuck on one? You don’t just get the sheet.

Addition within 20
Addition within 20 worksheet — Sums to 20, free printable with answer key

The answer key prints on a separate page.

What's on this sheet

First and second graders are expected to add fluently within 20, and the leap from 10 to 20 is bigger than it looks: it is the first time a child meets sums that cross ten. These sheets draw from every valid pair within 20, and multi-page packs run from easier to harder, so page one warms up and the last page stretches.

Why this sheet works

You control whether problems require crossing ten (carrying) or not. Turning carrying off gives a gentle start; turning it on drills exactly the facts children find hardest, like 8 + 7 and 9 + 6. Most workbooks mix these at random — being able to isolate them is what makes practice efficient.

How this one works

One question from this sheet, worked through a step at a time.

1 + 1

1+1
1+1=2
  1. 1 + 1. The answer stays under ten, so this is one to count on rather than split into tens.
  2. Start from the bigger one — you may pick, because 1 + 1 and 1 + 1 land in the same place — and count on 1: 2. So 1 + 1 = 2.