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Year 7 - Maths

Deepening understanding with fractions of a given amount

Understanding multiplicative relationships: fractions and ratio

Unit Summary

This unit introduces the concept of multiplicative relationsihps, and connects fractions to the idea of ratios. Ratios are then explored in depth and used to solve contextual problems such as those involving exchange rates and general conversions.

Lesson Summary

You will learn to find the original amount when given a fraction and the result.

Key Notes

  • To find the original amount, the result is divided by the fraction.
  • This can be seen visually through use of a bar model.
  • A double number line can also be used.

Vocabulary To Learn

  • Reciprocal: The reciprocal is the multiplicative inverse of any non-zero number. Any non-zero number multiplied by its reciprocal is equal to 1

Common Mistakes To Avoid

  • Only seeing the amount, not proportion. E.g £30 from £100 is no different to £30 from £60.

3 Quick Questions (With Answers)

1. Solve this in steps: explain the method from this lesson and why each step matters.

To find the original amount, the result is divided by the fraction. This can be seen visually through use of a bar model.

2. Use this key word in a maths sentence and explain it clearly. 'Reciprocal'

The reciprocal is the multiplicative inverse of any non-zero number. Any non-zero number multiplied by its reciprocal is equal to 1. Use this word when showing your method, then check your final answer is reasonable.

3. Spot and fix this common maths mistake.

Mistake: Only seeing the amount, not proportion. E.g £30 from £100 is no different to £30 from £60. Correction: Referring to the whole using bar models or fractions can emphasise the amount with respect to the whole.

More Lessons In This Unit

Browse all guides in the Year 7 Maths guide library.