Teaching and Group Activities for Understanding
Show a clock face on the IWB. Where does the minute hand point at quarter past? At half past. Quarter to? Draw lines to split the clock into quarters. Shade a quarter section. This is a quarter of the clock face. What’s the angle between the lines? [a right angle; 90 degrees; 90°]. Draw a right angle. A right angle is a quarter turn. Repeat to identify a half turn and a three-quarter turn. Note that the clock hands turn clockwise. Turning the other way is anti-clockwise.
-- In the hall or an outdoor space, give instructions to practise making quarter, half and three-quarter turns.
Show a picture. Close your eyes. Turn it 90° clockwise. Open eyes, what have I done? You have turned it through a right angle, a quarter of a full turn. Repeat, turning it through 2, then 3 then 4 right angles, both clockwise and anticlockwise. 2 right angles is half a complete turn, 4 right angles a complete turn.
-- Create patterns by rotating an irregular shape through successive right angles.
-- Create patterns by rotating a shaded 3 by 3 grid through successive right angles.
Draw a square and a rhombus. Which is a square? All the sides in each shape are the same length. Observe how each angle in a square must be a right angle. Show a large set square and how a ‘square’ corner is a right angle. Compare angles in the square and rhombus against the right angle of the set square.
-- Find examples of different types of angle in the classroom and around the school.
-- Classify angles <90° as ‘acute’ and >90° as ‘obtuse’.
Use the range of shapes on ‘Perpendicular and parallel lines’ (see resources) to explore lines that are vertical, horizontal, perpendicular and parallel. Look for examples of these around the classroom.
Use the ‘My square, not yours!’ in-depth problem-solving investigation below as today’s group activity.
Or, use these activities:
-- Sort shapes into a Venn diagram based on their properties.