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