Maths KS3: Ratios and fractions

Sanjeev Kohli has 20 friends coming round for dinner, but his mum’s recipe is only for four.

He needs to change each quantity and be able to scale up each ingredient.

Some of them have fractions, so this can get a bit tricky.

This clip is from the series Who Needs Maths?

Teacher Notes

This could be used to illustrate practical uses of ratio in changing recipes.

Students can then have a go at completing Sanjeev’s party menu, changing other recipes and thinking about different calculation strategies for more challenging numbers of guests or quantities of ingredients.

For homework they can then ask parents/carers for their favourite recipe, and scale it up to feed the whole class.

Curriculum Notes

This clip is relevant for teaching maths at Key Stage 3 and Third/Fourth Level in Scotland.