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Angles
Draw an angle and see what it is called, drag a protractor over it and read the scale, or estimate against the clock. Both scales are on the protractor, because reading the wrong one is the mistake every class makes.
Drag the protractor by its middle to sit the cross on the vertex, then drag the purple knob to turn it until the baseline lies along one arm. Read the scale that starts at nought on that arm.
Using it in class
Both scales, on purpose
A real protractor has two rings of numbers and children read the wrong one. So this one has both, and Hide the answer while we measure stops them checking before they have committed. Reading it is the skill, not owning it.
Estimating is marked kindly
Within 5° is a really good estimate, within 10° is close, and you always get told whether it was acute or obtuse rather than just "wrong". A child told 47° is wrong for a 45° angle learns that estimating is pointless.
The facts, on the diagram
Angles on a line, round a point, in a triangle and in a quadrilateral are buttons, not a list to copy down: press one and what is left over is worked out for you — and for a line or a point it is drawn in, and follows the arm as you drag it.
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