Number Bonds Worksheet Generator
Pick a target number from 5 to 20, choose missing-part or missing-whole practice, and generate a fresh, printable set of number bonds worksheets with an answer key.
Answer key
How to use it, with a worked example
Pick a target number from 5 to 20 -- that's the "whole" every problem on the sheet splits into. Choose how many problems you want, and which value should be blank: missing part, missing whole, or a mix of both. Turn on the bond diagram to print the classic three-circle layout, or leave it off for a plain part + part = whole line. Click Generate for a fresh random set, then Print.
Worked example, target number 10: the whole is 10, and one real split is 6 and 4 (6 + 4 = 10). In missing part mode, the sheet might show "10" on top with "6" and "___" below -- the student writes 4. In missing whole mode, the sheet shows "6" and "4" below with "___" on top -- the student writes 10. Both problems use the exact same 6-and-4 split; only which number is hidden changes.
Next step
Once a student can split 10 into 6 and 4 with number bonds, fact families show that same pair as all four related addition and subtraction sentences.
Fact Family Worksheet Generator →Number bonds practice splitting a total into two parts; the missing addend generator turns that same part-part-whole relationship into an addition sentence with one number hidden.
Missing Addend Worksheet Generator →
Frequently Asked Questions
What is a number bond?
A number bond shows how a number splits into two parts -- for example, 10 breaks into 6 and 4. It's usually drawn as three circles: the whole on top, connected by lines to its two parts below. It's a core Singapore Math technique for building number sense before kids memorize addition facts by rote.
What's the difference between "missing part" and "missing whole"?
In missing part mode the whole (the top circle) is always shown, and one of the two parts is blank -- for example, 10 splits into 6 and ___, so the child works backward from a known total. In missing whole mode both parts are shown and the whole itself is blank, so the child adds the two parts to find it. Mixed mode randomizes which of the three positions is blank on each problem.
What age or grade is this for?
Number bonds are typically introduced in kindergarten and first grade, usually starting with bonds to 5 or 10 before moving up toward 20. Missing-whole problems (straightforward addition) are usually easier and come first; missing-part problems (working backward from a total) are usually introduced once a child is comfortable with the missing-whole version.
Why leave a blank instead of just showing the answer?
The blank is the point -- the child practices recalling or figuring out the missing value, which is what builds real number sense rather than just copying an answer. Randomizing which of the three values is blank (rather than always the same one) also stops kids from pattern-matching the worksheet's layout instead of actually solving each problem.
Is every worksheet different?
Yes. Problems are generated randomly in your browser each time you click Generate, avoiding duplicate part/part/blank combinations within the same sheet, so you can print as many distinct practice sets as you need at the same target number. The answer key is generated from the same problems, so it always matches the sheet you printed.