Here is an angle with a protractor laid on top of it. Just by looking, does this look right to you, or does something seem off?

Look at the protractor already placed on each angle and the measure shown. Notice which number ring starts at zero on the baseline arm, that is the ring we follow. Notice the two angles on the last one and how they make a full turn together.

We measure on the board together now. One pupil comes up and reads the angle on the board's protractor aloud. Everyone else: keep your own protractor out at your desk, estimate the size silently in your head first, then get ready to agree or to say what you would change.

Today we work through four angles together, each one a step harder. We read the size on the board's protractor and check before moving on. At your desk, place your own protractor on the same angle and measure it too.

What we learned today

• Put the protractor's centre on the vertex first, then lay the baseline along one arm.
• Read from the ring that starts at zero on that arm.
• Estimate the size first, so you read the correct ring.
• For a reflex angle, measure the smaller angle and take it from 360°, because the two angles together make one full turn round the vertex.