Exponential Growth and Decay

This task introduces students to exponential growth and decay. It relates to compound interest for savings and depreciation of assets (e.g. cars).

Mathematical Strands

Number and Measure, Financial Maths, Algebra and Graphs

Prior Knowledge

An appreciation of percentages is required.

Relevance to Core Maths qualifications

  • AQA
  • C&G
  • Eduqas
  • Pearson/ Edexcel
  • OCR

Suggested approaches

Suitable for class discussion to introduce exponential growth and decay. The task would then be suitable for small group or individual work, according to students’ preferences.


In addition to this teacher guidance there are:

  • Information sheets on exponential growth and decay, with examples and questions posed relating to the shape of the graph (pdf)
  • Prepared templates for students to enter different y-values and sketch graphs
  • Repeated percentage change worksheet: compound interest (illustrated with ISAs), depreciation (illustrated with cars)
  • Geogebra worksheets

Relevant digital technologies

Spreadsheet for modelling; graphing software/Geogebra/calculator

Possible extensions

For related work, see the Core Maths Masters Subject Support, Strand: Graphs, Units 4 and 5. Possibly link with Cormathzadrine task for a further example of exponential decay.


Developed by Tom Carpenter at Bishop Challoner Catholic College.