Resource Portal

Here you can find STEM education resources.

Search and filter below, according to your preferences, to find free activities, videos or webinars to use.

The Legacy

You have been left one million pounds! How to spend or invest it over 50 years?

Publisher: Texas Instruments UK

Editor: Barrie Galpin

Author: Allan Duncan

Topic:  Mathematics

Tags  Interest ,  Tables ,  Modelling

This activity originates from a problem posed on the NRICH website. (

Your school has been left £1,000,000 in the will of an ex-pupil but there are conditions:

  • the school must benefit by spending part of the money every year,
  • the investment should have a lifetime of at least 50 years.

There are various possible models of investment and expenditure based on any balance being invested at a fixed interest/inflation rate. What model would you choose to ensure the best return for the school over a period of 50 years?

This is an opportunity to investigate what happens when variables such as interest, inflation rates and how much is spent each year are changed. Investigating how a small change in interest rates can affect the total income over different time periods can be enlightening. Investigating the impact of spending large amounts of money up-front can also provide valuable insights.

Five different models are provided in a tns file and students can explore the effect for example of changing inflation rates, of spending large amounts of money early etc.

A 3-page student handout is provided, and there are teacher notes to accompany the TI-Nspire document.

Publisher specific license