Maths · Bar Models: Missing Part
Bar Model Builder
Drag the number bricks into the bar model, then read off the answer.
Free to use and free to share. There is no sign-up, no score, and nothing a child does here is recorded or sent anywhere. What you may do with it, in full.
Loading the interactive exercise. Nothing you do here is saved or scored.
Why this works
The whole is fixed at 142. The parts you already know fill 97 of it, so the empty piece must be .
Helping a child through Bar Model Builder
Hints, least revealing first
- Drag every brick into the model first - the picture does the thinking.
- The parts you know sit inside the whole. The gap that is left over is what you are looking for.
- The ? brace marks the empty piece of the whole bar. Read the numbers on the bars underneath it.
When they finish it: “The model reads it out!”
3 11+ skills this exercise practises
Each of these has its own page, with a worked example on it.
- Add whole numbers or decimalsCalculate one addition with aligned place values.
- Solve a one-step number problemChoose and perform one operation in a short context.
- Subtract whole numbers or decimalsCalculate one subtraction with aligned place values.
You can reuse this. Here is exactly how far that goes
Tutors, teachers and editors keep asking, so this is the answer in writing rather than by email. You do not need to ask permission, and you do not need to tell us.
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Embed this exercise
Paste this into your own page and the exercise runs there, playable, for your readers or your students. It is 900 pixels tall by default and as wide as the column you put it in; change the height if your layout wants a different one.
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One exercise is a start, not a plan
A free diagnostic across all four subjects shows which maths skills to practise next, and in what order.