Year 5 - Maths
Know that the angles on a straight line sum to 180 degrees and use this to solve problems
Angles: compare, name, estimate and measure angles
Study Hub
Study Guides
This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils will compare the size of angles where there is a clear visual difference and use the terms acute, obtuse and reflex when describing the size of angles or amount of rotation with relation to right angles using a unit called degrees.
Lesson Summary
You know that the angles on a straight line sum to 180 degrees and use this to solve problems.
Key Notes
- Angles on a straight line have a sum of 180 degrees.
- To calculate missing angles you can use addition and subtraction.
- Use mental or written strategies to calculate with angles up to 180 degrees.
Vocabulary To Learn
- Sum: The sum is the result of adding two or more numbers.
- Opposite: If something is opposite, it is placed on the other side.
Common Mistakes To Avoid
- Pupils think that the angles on a straight line only applied to lines that are horizontal.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Angles on a straight line have a sum of 180 degrees. To calculate missing angles you can use addition and subtraction.
2. Use this key word in a maths sentence and explain it clearly. 'Sum'
The sum is the result of adding two or more numbers. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils think that the angles on a straight line only applied to lines that are horizontal. Correction: Ensure pupils are exposed to straight lines in a range of orientations, encouraging them to draw on the 180 degree angle and how this can apply to both sides of the straight line.
More Lessons In This Unit
- Angles in quadrilaterals Study Guide
- Angles in triangles Study Guide
- Describe rotations using the standard unit of degrees when compared to a right angle Study Guide
- Describe static angles using the standard unit of degrees when compared to a right angle Study Guide
- Draw angles accurately using a protractor Study Guide
- Estimate acute and obtuse angles using the standard unit of degrees Study Guide
- Know that the angles at a point sum to 360 degrees and use this to solve problems Study Guide
- Know that the angles in a full turn sum to 360 degrees and use this to solve problems Study Guide
- Measure the size of angles accurately using a protractor Study Guide
- Reasoning about angles in polygons Study Guide
- Review understanding and identification of right angles Study Guide
- Review understanding of angles as a measure of turn Study Guide
- Use the terms acute, obtuse and reflex when comparing angles to a right angle Study Guide
- Use the unit of degrees as a standard unit to measure angles Study Guide
Browse all guides in the Year 5 Maths guide library.