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MA19-07 Maths Coming soon

Growth and decay using repeated percentage multipliers

MA19-07

This lesson is coming soon.

In this lesson

Build a growth or decay multiplier from first principles and raise it to a power to calculate compound interest or depreciation over several periods, then express the process as the general formula A = P(1+r)^n.

What it covers

  • Building a growth multiplier (100% + r%) or decay multiplier (100% - r%) from first principles
  • Applying that multiplier repeatedly across n periods by raising it to the power n
  • Calculating compound interest and depreciation using this method
  • Generalising the repeated-multiplication method into the formula A = P(1+r)^n and using it directly to find a final amount

Key words

For: AQA GCSE 8300, Cambridge IGCSE 0580, Edexcel GCSE 1MA1, Edexcel IGCSE 4MA1, Eduqas GCSE C300, OCR GCSE J560

On the specification

BoardSpecStatement
AQA GCSE 8300R16Set up, solve and interpret the answers in growth and decay problems, including compound interest
Cambridge IGCSE 0580C1.13Calculate a given percentage of a quantity.
Cambridge IGCSE 0580E1.13Calculate a given percentage of a quantity.
Cambridge IGCSE 0580E1.17Use exponential growth and decay.
Edexcel GCSE 1MA1R16Set up, solve and interpret the answers in growth and decay problems, including compound interest
Edexcel IGCSE 4MA1F1.6GUse compound interest and depreciation
Edexcel IGCSE 4MA1H1.6AUse repeated percentage change
Edexcel IGCSE 4MA1H1.6BSolve compound interest problems
Eduqas GCSE C300FR16Set up, solve and interpret the answers in growth and decay problems, including compound interest
Eduqas GCSE C300HR17Set up, solve and interpret the answers in growth and decay problems, including compound interest and work with general iterative processes
OCR GCSE J5605.03aCalculate simple interest including in financial contexts.
For teachers

This GCSE Maths lesson teaches growth and decay using repeated percentage multipliers. By the end, students should be able to build a growth or decay multiplier from first principles and raise it to a power to calculate compound interest or depreciation over several periods, then express the process as the general formula A = P(1+r)^n. It works through three worked examples and the mistakes examiners report.