Expected level of development
Australian Curriculum Mathematics V9: AC9M5M04
Numeracy Progression: Understanding units of measurement: P7
At this level, students should understand when working with angles that they are describing the amount of turn or rotation, and develop their estimation and measurement skills.
Provide relevant contexts for students to explore angles. Model how to use a protractor and introduce the ‘degree’, develop their understanding that a full rotation is 360°, a quarter turn is 90° (right angle), a half turn is 180° (straight line) and a three-quarter turn is 270°. Students can use these benchmarks when estimating and comparing the sizes of angles.
Provide students with experience in using protractors. Explicitly teach why the numbers labelled are between 0° and 180° in a clockwise and anticlockwise direction.
Use dot paper grids to construct and represent angles. Order various representations of angles compared to 90°, which are less than, and which are greater than 90°.
Use interactive tools to estimate angles to the nearest degree.
Develop students’ reasoning and problem-solving skills when presented with problems about angles on a straight line and angles around a point.
Teaching and learning summary:
- Provide relevant contexts for students to explore angles.
- Encourage students to estimate angles before measuring.
- Model how to use a protractor and introduce the degree.
- Provide students with experience in using protractors.
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Teaching strategies
A collection of evidence-based teaching strategies applicable to this topic. Note we have not included an exhaustive list and acknowledge that some strategies such as differentiation apply to all topics. The selected teaching strategies are suggested as particularly relevant, however you may decide to include other strategies as well.
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Explicit teaching
Explicit teaching is about making the learning intentions and success criteria clear, with the teacher using examples and working though problems, setting relevant learning tasks and checking student understanding and providing feedback.
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Questioning
A culture of questioning should be encouraged and students should be comfortable to ask for clarification when they do not understand.
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Classroom talks
Classroom talks enable students to develop language, build mathematical thinking skills and create mathematical meaning through collaborative conversations.
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Teaching resources
A range of resources to support you to build your student's understanding of these concepts, their skills and procedures. The resources incorporate a variety of teaching strategies.
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Angles: measurement, construction, estimation
This resource provides teacher resources and student resources involving estimating angle size. It includes a self-check for student answers to questions.
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Skateboard skills
Students use geoboards, string and paper strips to create, name and classify different angles.
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Geometry: Foundation to Year 9
A comprehensive book containing an overview of geometry stages, as well as lesson ideas, and a teaching framework for geometry.
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Estimating angles
Teaching notes to support the use of an interactive that enables students to estimate the amount of turn (angle).
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Practice with protractors
A direct instructional approach lesson focusing on students using a protractor to measure various-sized angles of alphabet letters that make-up their name.
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Angles
Use these teacher slides to explore angles.
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Simple angles
In this unit students learn that the degree value of angles are simple fractions of a whole turn which is made up of 360°.
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