Subtraction within 20 Worksheet (Free Printable PDF)

What’s in the PDF

• Page 1 (Level 1, easier): It has six number line problems where children start at a dot and hop back, such as 15 − 6, plus six take-away sums that make a ten, like 16 − 6.
• Page 2 (Level 2, harder): It has twelve subtraction sums from 20 or less, six missing-number sums such as 14 − ? = 8, and a story problem about children getting off a bus.
• Page 3: an answer key for both levels.

Print one level at a time. If Level 1 feels easy, move straight on to Level 2.

How to teach subtraction within 20

Subtracting past 10 is easiest in two hops. For 15 − 6, hop back 5 to land on 10, then hop back 1 more to reach 9. A number line makes the hops visible. You can also think addition: what do I add to 6 to make 15? Children who know their addition facts well find subtraction much easier.

What to watch for

Children sometimes count the starting number as the first hop, so 15 − 6 becomes 10 instead of 9. Show them that a hop moves from one number to the next. Also watch for swapping the numbers around, as in 6 − 15; remind them the bigger number comes first in these sums.

Game: Bus stop

Line up 20 toys as passengers. Roll a die: that many passengers get off at the stop. Your child says the subtraction and counts who is left. Keep going until the bus is empty.

Everyday practice

Count back the days until a birthday, work out how many biscuits are left after snack time, or see how many pages remain in a book. Talking about what is left builds subtraction sense.

Questions to ask while they work

• Where will you land after the first hop back?
• Can you hop to 10 first?
• What addition fact can help you check?

Practise next

Try addition within 20, money, place value. Need a warm-up? Go back to subtraction within 10.