Number Bonds to 20 Worksheets for 1st Grade

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Grade 1MathCounting & Number SenseCCSS 1.OA.C.6

Skill: Finding the missing whole or part of number bonds with wholes from 11 to 20

Preview of the Number Bonds to 20 printable worksheet
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Teaching tips and what to try next

Suited to first graders who know their bonds to 10 well and can count on from a number. When a part is missing, many children find it easier to think "what goes with 7 to make 10, and then how many more," so encourage making a ten as a middle stop. Follow up with Missing Addends Within 20 or practice the same strategy in Make a Ten to Add.

10 versions, each with its own answer key

Same skill and layout, a fresh set of problems in every version, so children can keep practicing without repeating a page. Problems are not repeated between versions unless a skill has only a small number of possible problems (for example, the addition facts within 10).

Download all 10 versions (one PDF)All 10 answer keys (PDF)

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About this worksheet

Number bonds show a whole and the two parts that make it, drawn as three circles joined by lines. In first grade, children use bonds with bigger numbers to see how addition and subtraction fit together. If 8 and 7 make 15, then 15 take away 7 is 8. This first-grade worksheet practices number bonds with wholes from 11 to 20.

The page has twelve number bonds. In four of them, both parts are shown and children add to find the whole at the top. In the other eight, the whole and one part are shown and children find the missing part. Every part is at least 1, and every whole is a teen number or 20, so most bonds ask children to work across ten. Each of the ten versions has new bonds and its own answer key.

How to use it: show one bond with two colors of linking cubes. Snap the two parts into one tower, count the whole, then break it apart again. When a part is missing, encourage your child to count up from the part they know to the whole, or to make a ten first. For a bond like 16 and 9, going from 9 to 10 is one, and from 10 to 16 is six more, so the missing part is seven. Saying the matching subtraction fact out loud helps the link stick.

The answer key gives every missing number. For smaller wholes, try our Number Bonds to 10 worksheet. To see the same facts as equations, try our Missing Addends Within 20 worksheet.