Addition Within 20: Games, Strategies & Worksheet
Adding within 20 means totals up to 20, like 8 + 7 or 12 + 5. The key is using number bonds to 10 to bridge through ten quickly.
➕ Play the addition within 20 game 🖨️ Printable worksheet
Tricks that make it easier
- Bridge through 10: 8 + 5 = 8 + 2 + 3 = 13.
- Near doubles: 7 + 8 is double 7 plus 1 = 15.
- Add 10 then adjust: 9 + 6 = 10 + 6 − 1 = 15.
Try these
- 1 + 12 =
Answer
13 - 8 + 11 =
Answer
19 - 2 + 6 =
Answer
8 - 12 + 3 =
Answer
15 - 12 + 8 =
Answer
20 - 7 + 7 =
Answer
14
Common mistakes
- Counting the starting number again when counting on.
- Always starting from the first number instead of the bigger one.
- Guessing instead of using a known fact or bond.
A five-day practice plan
| Day | What to do (10 minutes) |
|---|---|
| Day 1 | Play Addition Adventure on this skill for 5–10 minutes. Read the explanation after every mistake. |
| Day 2 | Learn one trick from this page and use it out loud while you play. |
| Day 3 | Print the worksheet and try it without help. Mark it with the answer key together. |
| Day 4 | Play again and try to beat your personal best score or get three stars. |
| Day 5 | Mix it up: try the ⏱️ Timed test, or ask your child to explain the skill to you in their own words. |
Suits 1st Class and 2nd Class.
Frequently asked questions
What does addition within 20 mean?
It means adding numbers where the total is 20 or less.
How can I help my child get faster at addition?
Practise a few minutes every day with games and number bonds, and encourage strategies like counting on from the bigger number and bridging through 10 instead of counting from one.
Is there a printable version?
Yes. The free addition within 20 worksheet has 30 questions and an answer key, and you can make a new set in one click.