A scale is used to show how the distances on a map or plan relate to distances in real life

Scaling is the operation of changing one value to another using multiplication or division, using the same factor or divisor

A double number line is used to show the relationship between two values, in this case, the distances on the plan and those in real life

Use knowledge of multiplication and division to solve scaling problems in a range of contexts

Maths

Describe the relationship between two factors in a ratio context

Representing ratio in different ways

Explain how to represent ratio and to calculate unknown values

Use multiplication and division to calculate unknown values in ratio problems

Solve problems involving ratio

Explain how and why scaling is used to make and interpret maps

Solve problems involving scaling and ratio

Identify and describe the relationship between regular polygons using scale factors

Identify and describe the relationship between irregular polygons using scale factors

In this unit pupils will describe the relationship between 2 factors using a ratio grid to calculate unknown values They will use their knowledge of multiplication and division to solve scaling problems and identify and describe the relationship between two shapes using scale factors and ratios. In the future unit pupils will link fractions to ratio and look at ratio with exchange and conversions.

 In the prior unit pupils explained why the product stayed the same when one factor is doubled and the other is halved using knowledge of equivalence. They explained the effect on the quotient when scaling the dividend and divisor by the same amount. In this unit pupils will describe the relationship between two factors and use a ratio grid to calculate unknown values. 

In this unit pupils will describe the relationship between two factors, representing the relationship in different ways. They will build to using a ratio grid to calculate unknown values.

Ratio and proportion

How long is this room if the scale for the plan is 1 cm on the plan for every 50 cm in real life?

What value goes in the green box to represent a distance in metres in real life?

On a map with a scale of 1cm : 20km, what length on the map would represent 10km?

What is the value of a on this double number line?

What is the value of b on this double number line?

If you continued this number line, what distance on the map would represent 45 km on the island?

Use knowledge of multiplication and division to solve scaling problems in a range of contexts

Lesson outcome