Year 2 - Maths
Investigate how polygons can be joined and folded to form 3D shapes
Shape: discuss and compare 2D and 3D shapes
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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 learn that polygons can be described, sorted, compared and named according to the number of sides and vertices. They will describe 3D shapes, finding different ways to sort and compare them.
Lesson Summary
You will learn to investigate how polygons can be joined and folded to form 3D shapes.
Key Notes
- 3D shapes can have flat faces. Each face is a 2D shape.
- 2D shapes can be folded and joined together to build 3D shapes.
Vocabulary To Learn
- 3D / three-dimensional: A shape with three measurable dimensions, e.g. width, height and depth.
- 2D / two-dimensional: A shape with only two measurable dimensions, e.g. width and length, but no thickness.
- Face: The flat 2D surfaces of a 3D shape.
Common Mistakes To Avoid
- Children may apply the names of 2D shapes to 3D shapes (such as square and cube).
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
3D shapes can have flat faces. Each face is a 2D shape. 2D shapes can be folded and joined together to build 3D shapes.
2. Use this key word in a maths sentence and explain it clearly. '3D / three-dimensional'
A shape with three measurable dimensions, e.g. width, height and depth. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Children may apply the names of 2D shapes to 3D shapes (such as square and cube). Correction: Have examples of the confused 2D and 3D shapes (such as square and cube) for the children to handle and explore. Discuss what is the same and what is different about them.
More Lessons In This Unit
- Describe and name 3D shapes Study Guide
- Describe and name 3d shapes – prisms and pyramids Study Guide
- Describe and name polygons, including triangles and quadrilaterals Study Guide
- Describe, name and sort polygons, including pentagons, hexagons and octagons Study Guide
- Discuss and compare 3D shapes Study Guide
- Discuss and compare polygons Study Guide
- Find different ways to sort 3D shapes Study Guide
- Lines of symmetry Study Guide
- Recognise and sort polygons Study Guide
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