MA21-03 Maths Coming soon
Solve inverse proportion problems
MA21-03
This lesson is coming soon.
In this lesson
Solve an inverse-proportion word problem by identifying the correct (reciprocal) scale factor and applying it in the opposite direction to the given change.
What it covers
- Solving inverse-proportion word problems numerically using a unitary or scale-factor method
- Explicitly checking direction before calculating (does this go up or down?)
- Handling a non-integer (fractional/decimal) scale factor and interpreting the resulting answer sensibly in context
- Recognising that y=k/x means y is inversely proportional to x, as a label for the method already used
Key words
For: AQA GCSE 8300, Cambridge IGCSE 0580, Edexcel GCSE 1MA1, Edexcel IGCSE 4MA1, Eduqas GCSE C300, OCR GCSE J560
On the specification
| Board | Spec | Statement |
|---|---|---|
| AQA GCSE 8300 | R10 | Solve problems involving direct and inverse proportion, including graphical and algebraic representations |
| Cambridge IGCSE 0580 | E2.8 | Express direct and inverse proportion in algebraic terms and use this form of expression to find unknown quantities. |
| Edexcel GCSE 1MA1 | R10 | Solve problems involving direct and inverse proportion, including graphical and algebraic representations |
| Edexcel IGCSE 4MA1 | H2.5A | Set up problems involving direct or inverse proportion and relate algebraic solutions to graphical representation of the equations |
| Eduqas GCSE C300 | FR11 | Solve problems involving direct and inverse proportion, including graphical and algebraic representations |
| Eduqas GCSE C300 | HR11 | Solve problems involving direct and inverse proportion, including graphical and algebraic representations |
| OCR GCSE J560 | 5.02b | Solve simple word problems involving quantities in inverse proportion or simple algebraic proportions. |
For teachers
This GCSE Maths lesson teaches solve inverse proportion problems. By the end, students should be able to solve an inverse-proportion word problem by identifying the correct (reciprocal) scale factor and applying it in the opposite direction to the given change. It works through two worked examples and the mistakes examiners report.