Number Bonds to 20 Worksheets
Free printable number bonds to 20 worksheets with answer keys. Pairs that make 20, set as missing number questions: 13 + ? = 20, ? + 6 = 20 and 20 − 9 = ?.
Using this page
Pairs that make 20, set as missing number questions: 13 + ? = 20, ? + 6 = 20 and 20 − 9 = ?. The Common Core's Grade 1 standard asks children to find the unknown number in an addition or subtraction equation, and bonds to 20 build directly on bonds to 10. Suits around Year 1 and Year 2 in Australia and Grade 1 in the US (Common Core 1.OA.D.8), but use whatever level fits the child.
Tips
- Keep sessions short: one sheet of 10 to 20 questions a day beats a long session once a week.
- Mark the sheet together with the answer key and talk about the mistakes; each one shows what to practise next.
- Move to the next sheet when a child gets almost every question right without counting on fingers.
- Where it is offered, use the column layout for written methods and the across layout for mental strategies.
Worked example
13 + ? = 20. 13 is 10 and 3. 3 needs 7 to make 10, so 13 needs 7 to make 20. So 13 + 7 = 20. Bonds to 10 do the work: 3 + 7 = 10 becomes 13 + 7 = 20.
Common mistakes
Answering with the bond to 10 instead of 20, such as 13 + 3 = 20. Check by adding the two numbers.
Writing 7 for 20 − 7 = ? instead of 13. Read the whole question first.
How to use this generator
Choose the options above the sheet: the number of questions and the settings for this kind of worksheet. Every change makes a new sheet straight away, and New worksheet gives a different set of questions with the same settings.
Each sheet has a worksheet number printed at the top. Type the same number later, or keep the page link, to print exactly the same questions and answer key again. Leave Answer key page ticked to print the answers on a second page, then press Print. Every printed page carries the makekite logo and web address.
Common questions
Should bonds to 10 come first?
Yes. Once children know the pairs for 10, bonds to 20 follow quickly because each one is a bond to 10 with an extra ten.
How many questions should a child do?
Ten to twenty is plenty for daily practice. The 100-question drill sheet is for short timed practice once or twice a week.
Can I print the same worksheet again?
Yes. Note the worksheet number printed at the top, or keep the link in your browser's address bar, which ends with that number. Entering it later gives the same questions and answers.
Is it free?
Yes. There is no sign-up, and nothing you choose is sent anywhere: the sheets are made in your browser.