Number Bonds Worksheet Generator

About this tool

A number bond shows how a number can be split into parts. The whole sits at the top, the two parts sit below, and the lines between them remind students that the parts together make the whole. Bonds to 10 are the foundation for adding and subtracting within 20, and bonds to 100 prepare students for mental math with tens.

This generator makes the classic circle diagrams with the missing number left as an empty circle. You can choose bonds to any number from 5 to 100, decide whether the missing number is the whole, a part or a mix, and decide whether 0 may appear as a part. A three-part option asks students to split a number into three, and the fact family option asks for all four related addition and subtraction facts.

For one number at a time, the all-pairs sheet lists every way to make the number, from 0 plus the number to the number plus 0, with one part missing in each row.

How to use it

1. Pick a worksheet type. Missing number in a bond is the standard starting point.
2. Choose the number the bonds make. Bonds to 10 are the most important. Choose 20 and turn on the extra option to include wholes between 10 and 20.
3. Decide whether the missing circle is the whole, one of the parts, or a mix.
4. Press New worksheet for a new set and print. The answer key shows each filled-in circle in green.

Why number bonds matter

Students who know their bonds to 10 can add 8 + 5 by thinking 8 + 2 = 10, then 10 + 3 = 13. That strategy, making a ten, is what mental math looks like at this age. The more automatic the bonds, the easier the strategy.

A fact family shows how the same three numbers give two additions and two subtractions. With the bond 3, 7 and 10, students write 3 + 7 = 10, 7 + 3 = 10, 10 − 3 = 7 and 10 − 7 = 3. Seeing them together helps students understand subtraction as the opposite of addition.