Every number can be broken into two smaller numbers that go back together to make it. Five is 2 and 3, or 1 and 4, and a child who sees these pairs does not have to count every time they add or subtract. A number bond is a picture of this idea: the whole number sits on top, and the two parts sit underneath. On this page every item is a number bond with the whole shown, one part shown and one part missing, and the child writes the missing part.
Support sheets use wholes up to 5, standard sheets go up to 10, and challenge sheets use the larger wholes of 7 to 10. Hold up the whole on your fingers, fold some down, and see how many are left standing: the folded fingers and the standing fingers are the two parts.
What your child will learn
See a number as two parts
Find the missing part of a number
Know the pairs that make 5
Know the pairs that make 10
Common Core standard: K.OA.A.3
Worked example
The whole is 8 and one part is 3. The other part is 5, because 3 and 5 make 8.
Common mistake
Writing the whole again, or adding the two numbers that are shown instead of finding what is missing.
Helpful hint
Count up from the part you know until you reach the whole.