Use knowledge of equivalence when scaling factors to solve problems

Maths

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

 In the prior unit pupils explained how to identify a multiple or common multiple to solve problems in a range of contexts. In this unit pupils will explain why the product stays the same when one factor is doubled and the other is halved using knowledge of equivalence. They will explain the effect on the quotient when scaling the dividend and divisor by the same amount.

Using equivalence to calculate

Use the complete equation to work out the missing factor in the equation beneath. It is a 2-digit number.

Use the complete equation to work out the missing product in the equation beneath.

 Use the complete equation to work out the missing factor in the equation beneath. It is a 2-digit number.

Which pairs of factors could be used to complete this equation?

What is the missing factor in this equation? It is a 2-digit number.

What’s the missing factor in the equation in the diagram?

Use the equation 255 ÷ 17 = 15 to work out the missing product. 15 × 17 = {{ }}

What’s the missing number in this equation? 45 × 20 = 15 × {{ }} 

Andeep scales the equation 32 × 30 = ___ to make it easier to answer. Which of these equations is the most sensible and efficient choice?

Laura is trying to find the product of 55 × 8 and writes some possible equations. Which is correct and will help Laura find the product?

Use scaling to help you find the product: 16 × 25 = {{ }}

This lesson will soon be taken down.

Use knowledge of equivalence when scaling factors to solve problems

Lesson outcome