This game provides an engaging way to estimate angles. Instant feedback enables students to improve their estimation skills.
Start the lesson by asking students what they know about angles around a point. Draw out names of angles (acute, obtuse, reflex, right-angled) and landmark angles (90 degrees, 180 degrees, 270 degrees, 360 degrees).
Draw acute, obtuse and reflex angles on the board and ask students to estimate their size. Encourage justification for estimates.
Draw another five angles on the board and challenge the class to make better estimates than you can. Invite students to estimate each angle, and then estimate the angles yourself. Then measure each angle with a protractor. The closest estimate gains a point.
You may wish to use the GeoGebra applet below - move the dot to change the angle, and tick/untick the box to show/hide its measurement.
Demonstrate the interactivity at Level 2 before setting the group off to work in pairs. The challenge is to score more than 50 points in 10 goes.
Keep a record of the highest score on the board. How close to 100 points can any pair get? This could be a long-term challenge.
Pairs could move on to Level 3 when appropriate.
Which angles are easy to estimate?
What strategies can you use to improve your estimates?
Paper Plate Angles are a great way to get students to engage with angle terminology. This YouTube Video shows how to construct them.