Addition Within 20 Worksheets

Using this page

Two numbers with a total up to 20, including the bridging facts such as 8 + 5 and 9 + 7 that cross ten. The Common Core asks Grade 1 children to add within 20 and to be fluent within 10, and by the end of Grade 2 to know all sums of two one-digit numbers from memory. The sheet mixes easy and bridging facts so children practise both. Suits around Year 1 and Year 2 in Australia and Grade 1 in the US (Common Core 1.OA.C.6), 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

8 + 5. Make ten first: 8 needs 2 more to make 10, so split 5 into 2 and 3. 8 + 2 = 10, then 10 + 3 = 13. So 8 + 5 = 13. The same trick works for 9 + 6 (9 + 1 + 5 = 15) and 7 + 6 (7 + 3 + 3 = 16).

Common mistakes

Losing track when counting on more than five. Making ten is more reliable for the facts that cross ten.

Writing teen numbers back to front, such as 31 for 13. Say the number aloud: thirteen is ten and three.

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

What is making ten?
It means splitting one number so that the other reaches 10 first, then adding what is left. It turns hard facts like 8 + 7 into 10 + 5.

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.