Number Bonds to 20 Worksheets

Give twelve bonds as a ten to fifteen minute sheet, or six if the facts are new. Encourage the child to bridge through ten: for 17 split into 9 and a missing part, think 9 needs 1 to reach ten, then 7 more, so the missing part is 8. Check with the answer key, then have them explain one bond aloud. Repeat with a fresh version a few days later.

Bonds to 20 are where memorized pairs to 10 meet the make-a-ten strategy. A child who knows 7 and 3 can work out the neighbors by using the same structure. Many first graders know 8 + 2 but not 8 + 9, and the diagram forces the search for the missing part. The usual error is to add two visible numbers even when the top circle is one of them.

Whole up to 20 matches this page; drop to 10 if a child needs warm-up pairs, or raise it to 100 for two-digit work. Because wholes begin at 2, some bonds are small and make easy wins in the mix. Use six problems when the facts are new and twenty to build speed. Pair with ten frames so the child can see the split.

Why do some bonds on this page have small wholes?

Wholes run from 2 to 20, so small bonds appear among the teens. They give easy wins, and they keep recall of the basic pairs fresh alongside the harder ones.

What is the easiest strategy for a teen whole with one part given?

Make ten: split the known part so one piece completes ten, then count what remains. A ten frame or counters make that move easy to see for a child. Counters or a ten frame make the move visible.

When should my child move to the 100 setting?

When bonds to 20 are quick and they add and subtract two-digit numbers on paper. At 100 the diagram becomes two-digit addition and subtraction, so it is not a good first step.