Addition Within 20
Grade 1 - Math - Challenge Me
Worksheet 19 + 4 = ____
8 + 11 = ____
5 + 13 = ____
8 + 4 = ____
5 + 11 = ____
4 + 10 = ____
4 + 9 = ____
7 + 9 = ____
5 + 12 = ____
18 + 0 = ____
Grade 1 - Math
Grade 1 Addition Within 20 Worksheet
6 printable versions - Challenge Me - About 4 minutes each
Worksheet 1About this worksheet
Adding within twenty introduces the step that makes arithmetic work: crossing the ten. A child who can answer 8 + 3 by counting on will eventually need the faster route of making ten first, taking two from the three to fill the eight up to ten, then adding the one that is left. This worksheet mixes totals below ten, which your child can already handle, with totals above ten that require the new strategy, so the contrast is visible on a single page. Some questions are illustrated and some are not, because the goal is to move from counting objects towards recalling facts. If your child is still counting every question on fingers, that is normal at this stage and worth practising rather than correcting.
What your child will learn
- Add two numbers with a total up to 20
- Cross the ten when adding, for example 8 + 5
- Use the make-ten strategy to add faster
- Recognise teen totals as ten plus some ones
Worked example
For 8 + 5, take 2 from the 5 to make 8 into 10, then add the remaining 3: 10 + 3 = 13.
Common mistake
Losing count when the total crosses ten and landing one out.
Helpful hint
Fill up to ten first, then add what is left over.
Questions parents ask
- What is the most common mistake with addition within 20?
- Losing count when the total crosses ten and landing one out.
- How can I help my child with addition within 20?
- Fill up to ten first, then add what is left over.
- Are these 1st grade math worksheets free to print?
- Yes. All 6 printable versions on this page are free to download and print, with no account needed.