Addition and Subtraction Within 20 Games Online Free
Mixed addition and subtraction questions, all within 20. Read the sign carefully: some add, some take away.
Type answers on your keyboard, or tap the number pad.
Practise these again:
What does fluency within 20 mean?
Being fluent within 20 means answering any addition or subtraction fact up to 20 quickly and accurately, without counting. In the US, it’s a second-grade goal.
Mixing the two operations checks that children notice the sign. If one kind is much slower, practise it on its own with addition within 20 or subtraction within 20.
How to play Addition and Subtraction Within 20
- Choose the 60-second challenge or untimed practice, then press Start.
- Type each answer on your keyboard or tap the number pad. It’s checked as soon as you’ve typed enough digits, or press ✓.
- Get one wrong and you’ll see the right answer, and the question comes back a little later.
- At the end, check your score and the facts to practise again.
Addition and Subtraction Within 20 skills
- Fluency with addition and subtraction within 20
- Switching between adding and subtracting
- Reading the operation sign
Level: Grades 1–2 (ages 6–8)
Tips for mixed addition and subtraction
Look at the sign before the numbers. It’s the most common reason for a wrong answer in mixed practice.
Use one fact for both: if 9 + 6 = 15, then 15 − 6 = 9 and 15 − 9 = 6.
Practise in the 60-second challenge once accuracy is good. Speed comes from knowing facts, not rushing.
Addition and Subtraction Within 20 questions and answers
What numbers are used?
Additions have totals up to 20, and subtractions start from a number up to 20 and never go below zero.
Why mix addition and subtraction?
In real problems the operation isn’t always the same, so children need to read the sign and switch. Mixed practice also shows how the two are connected.
Is this good for testing fact fluency?
Yes. The 60-second challenge is a quick fluency check. Your best score is saved in your browser, so you can see progress over time.