One of two equal parts of a whole. To divide into two equal parts.

To become twice as many / to multiply by two.

A factor is a number which exactly divides another whole number.

A product is the result of two or more numbers multiplied together.

Identify missing factors when one factor is 2

Maths

Double 2-digit numbers and record as multiplications where one of the factors is 2

Explain how doubling and halving are related

Halve even 2-digit numbers and multiples of 10

Use knowledge of doubling, halving and the 2 times table to solve problems

In this unit pupils will learn how multiplication with 2 as a factor relates to doubling and how we can see halving as the inverse of doubling, deriving the related halving fact from a known double. In the future unit pupils will double and halve 2 digit numbers. Pupils will use knowledge of doubling and halving and the 2x table to solve problems.

In the prior unit pupils represented the 2x 10x table in different ways. They explained the relationship between adjacent multiples of 2/10 and how factor pairs can be written in any order. In this unit pupils will learn how multiplication with 2 as a factor relates to doubling and how we can see halving as the inverse of doubling, deriving the related halving fact from a known double. 

In this unit pupils will learn how multiplication with 2 as a factor relates to doubling and how we can see halving as the inverse of doubling, deriving the related halving fact from a known double.

Multiplying by 2, doubling and halving (factors and products)

Use the bar model to find the missing factors in the equations.

What is the missing factor in this equation? 2 × {{ }} = 14

Which of these problems could I use halving to find the missing factor?

Find the missing factor is this equation. {{ }} × 2 = 30

There are 16 gloves in a drawer. How many pairs of gloves can be made? {{ }} pairs

Which facts will help you to find half of 16 by partitioning the parts?

These multiples of 10 have been halved. Match them correctly.

Look at the image of Base 10 blocks. What is half of 22?

Find half of 30 by partitioning. Half of 30 = {{ }}

Identify missing factors when one factor is 2

Lesson outcome