What the lesson is about

This uses a horse-racing game to look at experimental and theoretical probability and is aimed at key stage 3 pupils.

Aims: pupils will -

- understand how experimental probability approaches theoretical probability as the number of trials increases;

- calculate and represent probability in fractional, decimal and numeric forms;

- use lists and tables;

- conduct probability experiments.

Getting started

Line the pupils up behind horses numbered two to 12 and start the race. Use two dice to determine the movement of the horses, so each time its “number” comes up it moves forward a square. Run the race five times and record the results on a spreadsheet. Ask why some horses are more likely to win. Let pupils make a probability grid to calculate possible combinations of each horse moving forward a space. Compare this theoretical probability with the results. Ask pupils to consider what would happen if there were more races.

Taking it further

Print off the “Think-Tac-Toe” sheets from the link below on the TES website. Each sheet has a box split into nine activities, such as the probability of drawing a certain card from a pack, creating a word search involving probability terms and designing a game that gives a player a 30 per cent chance of winning. In pairs, ask the class to tackle the activities. Once each pair has completed a row, go through the exercises with the class and discuss any errors.

Where to find it

The original lesson, plus activity sheets, was uploaded by MicheleCF and can be found at www.tes.co.ukprobability-horserace.