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P5 Maths · bar models

Maths Model Lab

Bar models, one small step at a time. Your child draws on a blank sheet, just like the exam. Then the Lab shows a worked model, step by step, and asks: does your sheet have this?

Free, on your That Science Thingy account. Sign in and the Model Lab opens straight away.

The Blank Sheet: an At first model with Mei 4 boxes and Raj 1 box, and an End model where both get 30 more, with a bracket showing Mei equals 2 Rajs.
A neat model on the blank sheetA real Model Lab screen · View larger

The hardest part is the first line.

A blank sheet, like the exam
Draw with a finger or a mouse. A wobbly box tidies itself into a neat bar. A line cuts it into units. A curve becomes a bracket.
Picture first, sums last
Stories turn into bars before any numbers. Children see why “the total stays the same” before they meet it in a question.
Compare, step by step
After drawing, the worked model appears as Step 1, Step 2 and so on. Steps the Lab can already see on the sheet are ticked for them.
No red crosses
A step that is not there yet says “not yet”, and the child can fix the sheet straight away.

The 7 Model Steps

The same routine for every bar-model question, each step one small action.

  1. 1. Who?

    One bar for each person, all starting at the same line.

  2. 2. Before and after?

    A change word, like gave, spent or bought? Then draw an At first model and an End model.

  3. 3. One sentence, one drawing

    Read one sentence. Draw only that. No sums yet.

  4. 4. What stayed the same?

    The total, the gap, one person, or nothing? Keep that part the same.

  5. 5. Put the ?

    Whose bar, and when? One bar, or all of them together?

  6. 6. Find 1 unit

    Three short lines: units = number, 1 unit, then the answer.

  7. 7. Check in the story

    Put the answer back into every sentence.

Compare screen: Step 1 Who, Step 2 Before and after, and Step 3a, each with a small worked picture and a green note saying I can see this on your sheet.
Compare: step by stepA real Model Lab screen · View larger

Five short stations, from seeing to drawing alone

Story Theatre: Ben has 1 unit and Ali has 3 units, after the marbles slid together into bars.
Marbles turn into barsA real Model Lab screen · View larger
  • Story Theatre: real things slide together into a bar.
  • Sandbox: give, spend and add, and watch what stays the same.
  • Bar Builder: make one sentence into bars of the right length.
  • Finish the Model: help that steps back, from watch to your turn.
  • Blank Sheet: the real thing, drawn alone, then compared.

For parents

The Model Lab uses the same login as the rest of the site. On a parent account it first asks who’s doing maths today, so your child plays on their own card.

Your parent dashboard then shows their stars, each Blank Sheet attempt, the step they most often mark “not yet”, and the drawing itself.

A window titled Who's doing maths today, with two child cards to choose from.
Pick your child’s cardA real Model Lab screen · View larger
Parent dashboard: a child's Blank Sheet attempt with each of the 7 steps marked and their saved drawing.
Your child’s drawing, step by stepA real Model Lab screen · View larger