Explain why the product stays the same when one factor is doubled and the other is halved

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

What is the missing factor in the equation in this diagram? 

What is the missing number in this equation? 8 × 10 = {{ }} × 20

What is the missing number in this equation? 6 × 13 = 26 × {{ }} 

 Which expressions are equal to 34 × 24?

Use scaling to help you find the product:  5 × 46 = {{ }}

Use scaling to help you find the product: 50 × 36 = {{ }}

What multiplication fact is represented by the array?

What is the missing number in this equation? 6 × {{ }} = 72

What is the missing number in this equation? 11 × {{ }} = 220

Starter Quiz