### Teaching and Group Activities for Understanding

**Day 1 Teaching**

Using an online protractor, show how to align the protractor to read the angle. Point out how the numbers of degrees go both anticlockwise and clockwise; this is the case on many protractors! Measure angles of 90°, 180°, 270°. Show different angles for children to estimate then measure.**Group Activities**

Use the in-depth problem-solving investigation ‘Nine-pin triangles’ from NRICH as today’s group activity.

Or, use this activity:

-- Accurately draw and measure angles.

**Day 2 Teaching**

Introduce acute, obtuse and reflex angles.

Launch ‘Angles’ from www.mathsisfun.com. Scroll down to 'Try it yourself' and move the top line of the angle anticlockwise to gradually increase it from 1° to 360°, asking children to watch the angle titles at the side. Draw some angles, and children classify them as acute, obtuse or reflex.

**Group Activities**

-- Classify angles as acute, obtuse or reflex through shape investigation.