Addition within 20 Worksheet (Free Printable PDF)

What’s in the PDF

• Page 1 (Level 1, easier): It has six double ten frame sums such as 9 + 4 and 8 + 5, where the dots show how to make 10 first, plus six doubles and near doubles like 6 + 6 and 6 + 7.
• Page 2 (Level 2, harder): It has twelve number sums with totals to 20, six missing-number sums such as 8 + ? = 15, and a story problem about pages read in a day.
• 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 addition within 20

Once children know their pairs that make 10, they can use them to add bigger numbers. For 8 + 5, take 2 from the 5 to fill up the 8 and make 10, then add the 3 that is left: 13. Ten frames show this clearly. Doubles are the other big shortcut: if your child knows 6 + 6 = 12, then 6 + 7 is just one more.

What to watch for

Many children still count on in ones from the first number, which is slow and error-prone past 10. Gently show the make-10 step with counters. Also watch for children who start counting on from the wrong number, saying 8, 9, 10 for 8 + 2 and ending one short.

Game: Double trouble

Roll two dice. If you roll a double, say the total and score a point. If you roll a near double, like 4 and 5, say the double first and then add one. First to five points wins.

Everyday practice

Add scores in a board game, count how many pieces of fruit are in two bowls, or work out how many people will be at dinner if guests come. Small real totals give quick practice without a pencil.

Questions to ask while they work

• How many more do you need to make 10?
• What is the double that helps you here?
• Can you check your answer by adding the other way round?

Practise next

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