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AvailableSecondary mathematics

Expanded Tabletop

Expansion of the square of a sum

Overview

A square tabletop is enlarged by adding strips of equal width along its edges. Students investigate how the total surface area changes and discover how geometric decomposition leads naturally to the expansion of a square. The lesson connects area reasoning, visual representation, and algebraic structure.

Key ideas

  • Area models
  • Algebraic representation
  • Visual reasoning
  • Expansion of expressions

How this lesson is built

This lesson follows the MSS learning flow: situation, observation, exploration, representation, formalisation, and application.

Read the full learning flow

Resources

  • Lesson designReady
  • Teacher guideReady
  • Student activitiesReady
  • Assessment ideasReady

Lesson video

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