Grade 1 · Year 2 · Class 1 · ages 6–7 · Subtraction
Subtraction within 20: Grade 1 practice
Subtracting within 20, including crossing back over 10. Eight questions at a time, instant feedback and a mastery score from 0 to 100.
This practice needs JavaScript. You can still print a subtraction within 20 worksheet with an answer key.
Right answers raise your mastery score (more on harder questions) and wrong ones lower it a little. Your best score is saved on this device, and in your account if you log in.
The idea in one minute
To work out 15 − 8, count back to 10 first (5) and then take away the other 3.
Try these on paper first
One question at each level. Tap a question to see the answer.
Easy 13 − 7 =
Answer: 6
Medium 10 − 7 =
Answer: 3
Challenge 10 − 8 =
Answer: 2
More ways to practise subtraction within 20
- Printable subtraction within 20 worksheet with an answer key (new questions every time)
- Bubble Pop Maths: Pop the bubble with the right answer. 60 seconds, streaks and bonus points.
- All Grade 1 practice · Subtraction worksheets
Related skills
- Subtraction within 10 (Grade 1)
- Subtracting within 20 word problems (Grade 1)
- 2-digit subtraction (Grade 2)
- 2-digit subtraction word problems (Grade 2)
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FAQ
Subtraction within 20: questions
What grade is subtraction within 20?
It is usually taught in Grade 1 (Year 2 in England, Class 1 in India, ages 6–7), though schools and countries differ. Try the grade above or below if it feels too hard or too easy.
What does a subtraction within 20 question look like?
For example: "10 − 7 =" The answer is 3. To work out 15 − 8, count back to 10 first (5) and then take away the other 3.
What should I learn before and after subtraction within 20?
Before it, try subtraction within 10 (Grade 1). After it, move on to subtracting within 20 word problems (Grade 1).
How can I get better at subtraction within 20?
To work out 15 − 8, count back to 10 first (5) and then take away the other 3. Practise a little every day, read the hint after each wrong answer, and use the printable worksheet when you want to write it out.
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