Ratio and Proportion

Overview

Ben and Katie are called upon to sample some tasty treats, as they learn how ratios are used in the food industry to get recipes just right. Later, Tony Robinson explains how the charity Comic Relief used ratios to share out the huge amounts donated to last year’s campaign. We see how to:

• express relationships between quantities as ratios
• keep ingredients in the same proportions when scaling up a recipe
• solve ratio problems using a unitary method for calculation
• share an amount in a given ratio

The programme shows how understanding of ratio and proportion is applied in different contexts in the real world. Clear visual demonstrations develop the concepts and explain the techniques. Calculators are used where appropriate, but many of the examples are tackled mentally, and use values that are simple enough for most pupils to follow.

The content is linked to the requirements of GCSE Intermediate Mathematics. It includes tips for answering exam questions, and a discussion of a typical exam error (‘Tick or Trash’).

Ratio notation and equivalence are mentioned but not developed in detail: it is assumed that pupils will have some knowledge of these before viewing. Although the idea of units is included, it is not specifically discussed: this could be treated more fully after viewing.

The programme could be used to introduce the types of problem that are frequently tested in the GCSE examination and to describe their methods of solution. It should also help pupils to appreciate that these methods are widely used to solve problems in the real world.