Numberless Protractors
  • Print onto OHP transperency, 10 to a page
  • Easy to use
  • Provokes 'reasonableness of answer' approach to measuring angles
  • Requires users to count angles in 'lots of 10' and then estimate the last part of an angle
Numberless_Protractor.png
Angle Estimation sheet
Challenge students to estimate and record their answers first, and then use a 'Numberless Protractor' to measure each angle, calculate the error.
Using a timer will create some 'urgency' for students to complete the task quickly. IWB software has built-in protractors (typically, a traditional protractor) and the Maths 300 lesson Angle Estimation has some some useful software.
Angle_Estimation.png
Screen dump of part of Angle Estimation sheet