Display the spot-the-mistake image as pupils settle. Take three hands-up answers, not open call-outs. Listen for pupils noticing the middle dot is off the corner or the bottom edge is not along an arm.

Don't reveal the correct placement yet — that lands in Watch and Notice, where we'll give these the proper names vertex and baseline. Keep this to about a minute.

Model the same habit every time: centre on the vertex first, then baseline along an arm from 0. Say it verbatim each time.

40 acute: point at 0 on the baseline arm, trace that ring up to 40°. Show the other ring reading 140 (140°) so they see why the ring matters. Ask which arm we started counting from.

130 obtuse: head off the wrong-ring slip — estimate first (more than a right angle, over 90°), then read 130°.

90 right angle: both rings meet at 90°, so it never matters which you read here.

290 reflex: protractor only reaches 180°. Show the small angle is 70° and the reflex angle is the rest of the way round. Together they make a full turn of 360° round the vertex, so 360 − 70 = 290°.

The inner scale is on for this lesson because reading the right ring is the whole point.

This round is for talking it through together — pupils take turns at the board and the class agrees or corrects out loud.

Set three or four different angles in turn, all within 0–180°. Before each read, ask the class to estimate (bigger or smaller than a right angle?) so they catch a wrong-ring reading before it happens. Rotate four pupils to position the protractor and read aloud.

Watch for the centre drifting off the vertex — the commonest slip. Revoice a good fix: centre on the vertex, then swing the baseline onto the arm.

These are the practice questions — pupils take turns at the board, check each answer, and the class confirms before moving on. Keep the board work brisk rather than over-explaining.

The 35° catches careless readers who grab 145° off the wrong ring — make them estimate first. The 290° reflex needs the whole-turn step: the small angle is 70°, and 360 − 70 = 290 because the two go all the way round; talk it through as a class. Use the Check ✓ as part of the narration: yes — that's it.

Quick recap of the centre-then-baseline habit. Hold up one protractor and re-state the placement order one last time before the activity-book practice.