Take three hands-up answers, not open call-outs. Don't settle the argument yet — the disagreement is the hook. How could we settle this without walking each one? is the question that opens the lesson.

Before the Lesson

• One large demonstration metre stick for the front, plus one metre stick per group of four or five.
• Three pupils' rulers and a Maths book to hold against the demonstration metre stick.
• Mark three routes in your chosen space (yard, hall, or corridor) with chalk or tape: a Short route under 1 m, a Medium route around 5 m, a Long route 10 to 15 m.
• This lesson uses real metre sticks at pupils' hands throughout — there is no IWB measuring widget. Do not strip the metre-stick prep on the assumption the steps run on screen.

This is a real demonstration with the metre stick at the front, not an on-screen widget. Hold the stick up at eye level so the whole class can see the marks.

• Board rail — take one estimate before you lay the stick; this trains the anchor habit.
• Maths book — name aloud that it's under a metre, so centimetres are the sensible unit. Read the length off the stick to the nearest cm.
• Door — the most useful anchor of the day. A classroom door is about 2 m; revoice so now you know what 2 m looks like, you can judge other heights against it.

Keep the estimate-then-measure order every single time — the moment you measure before estimating, the thinking the lesson exists to build is gone.

This round is for pupils to measure at their desks and around the room with their own group's metre stick — circulate and catch alignment slips on the spot. Each group has one metre stick and takes turns; the watchers check the start point and gaps and call the reading. The class reads aloud and you reconcile any disagreement as you circulate.

• Insist the estimate is written before the stick comes out for each length.
• The desk and door-frame are best in metres with a decimal (e.g. 1.2 m); the front-to-back distance needs the stick laid end-over-end several times — watch for pupils losing count.
• Revoice a good anchor aloud: Liam said the desk is a bit longer than the door is wide — that's using one length to judge another.

This round is the practice bank — real routes are marked around the room (or in the hall/yard). Assign each group one route so the physical load stays manageable, then pool readings on the board so the whole class ends with all three. Keep the rhythm brisk; the class confirms each reading aloud at the end.

• Each group measures one route only with its own metre stick — this keeps the number of end-over-end lays per group small enough to finish in the slot.
• Have pupils calibrate their own pace against the metre stick first (one step is shorter than a metre for most ten-year-olds), so the pacing estimate is their own, not a fixed figure.
• Route A is shorter than a full step — don't let pupils pace it. Compare to half a metre stick or a Maths book held lengthways, then check.
• Reconcile readings aloud at the end: the closest estimate of each route is the talking point, not the exact number.

Close by pointing back at the opening corridor-versus-playground bet — did the measuring settle it? Link forward: today we measured to the nearest metre or centimetre, next lesson we get more precise, down to the millimetre.