Number Bond Generator

Builds a sheet of number bonds — pairs that make a given total with one part missing — to ten, twenty, a hundred or a thousand. Every question is computed and checked directly — not a fabricated or AI-guessed fact.

How many questions

Between 1 and 30. Ten fills a page.

Level

Seed (optional)

A word reproduces the same sheet, so a whole class can be given the identical set.

Gentle bonds to 10 and 20, standard to 100, stretch to 100 and 1,000.

Paper size

Print size

Margin

Millimetres of blank edge, 5 to 40.

Turn the paper sideways

Room to answer in

How to print this, or save it as a PDF

There is no PDF to download, and there does not need to be. Open the print command in your browser and choose “Save as PDF” as the destination. The page addresses and dates a browser normally prints across the top and bottom are already kept off.
Set the scale to 100%, not “fit to page”. This sheet is already the exact size of the paper you chose, so anything that resizes it makes every measurement on it wrong.
Leave the paper size in the dialog set to the same one you chose here.

Your questions will appear here.

What this generator does

Bonds to ten and twenty are the foundation mental arithmetic is built on, and the only thing that makes them automatic is volume. The missing part appears on either side of the plus sign from question to question, which matters: a child who has learned the pattern rather than the fact often stalls the first time the gap moves to the front.

How to use this tool

Choose how many bonds you want and which total to make.
Press make questions, and work through the sheet.
Show the answers to mark it.
Enter a seed word to rebuild the same sheet later.

Understanding the controls

How many bonds: One to thirty. Bonds are the one topic where a thirty-question sheet done at speed is genuinely more use than ten done carefully.
Level: Gentle makes ten and twenty, standard makes a hundred, and stretch mixes a hundred and a thousand. The total is what changes; the reasoning does not.
Seed: A word rebuilds the identical sheet, so the same bonds can be given twice — useful for measuring speed on a repeat run.
Show the answers: Reveals the missing part for every bond at once, as a numbered list matching the questions.

Common use cases

Early-years number-bond practice
Mental-maths fluency building
Quick daily warm-ups
Giving a whole class the identical sheet from a shared word

How this generator works

The total is fixed by the level, one part is drawn and the other is whatever completes the bond. Which side of the plus sign the gap sits on is drawn separately, so it varies within a sheet. Each answer is read back out of the printed text and added to the part shown; that total must equal the target exactly.

Randomness and fairness

The known part is drawn across the whole range between one and one below the total, so very small and very large parts appear as often as middling ones. The gap's position is a separate draw from the numbers themselves.

For how randomness is produced across the whole site, see how Generate Random works.

Limitations and good to know

Neither part is ever zero or the total itself, so the two edge cases of the bond are not practised here.
Only two-part bonds are produced; three-part bonds to the same total are a different exercise.
Seeding is for repeatability rather than secrecy: it is not cryptographic randomness, and the same word always produces the same bonds.

Practical tips

Speed matters more than accuracy once accuracy is there. Bonds need to be recalled, not worked out.
Do a short burst daily rather than a long sheet weekly; this is one of the few topics where that genuinely holds.

Privacy and your data

The sheet is built in your browser and never leaves it. Your seed and level are not uploaded, not stored and not sent anywhere.