# Dividing by 2

## How do you divide by 2?

Dividing by 2 is the same as halving a number or a set of objects.

There are different methods for dividing by 2. We are going to look at four of them here: sharing, grouping, using a number line, and repeated subtraction.

## Dividing by 2 : Sharing

There are 10 stars. To divide them by two, we need to share them equally between two groups:

Share the stars between two circles. To make sure you do this equally, add one star to the first circle, then one star to the second circle. Go back to the first circle and repeat until there are no stars left.

There are 5 stars in each group.

This means that 10 ÷ 2 = 5.

## Dividing by 2 : Grouping

There are 8 umbrellas. To divide them by two, we can sort them into groups of 2:

Draw a circle around each group of 2 umbrellas until there are no more groups of 2 left.

There are 4 groups of 2 umbrellas.

This means that 8 ÷ 2 = 4.

## Dividing by 2 : Using a number line

What is 12 ÷ 2?

Draw a number line that goes up to the number you are dividing. In this number sentence, it is 12.

Then, starting at zero, make jumps of 2 along the number line until you cannot make any more jumps of 2.

There are 6 jumps of 2 from 0 to 12.

This means that 12 ÷ 2 = 6.

## Dividing by 2 : Repeated subtraction

What is 14 ÷ 2?

Take away 2 from the number you are dividing. In this number sentence, it is 14.

Keep taking away two from each new answer until you reach zero.

Two had to be subtracted 7 times in total before the answer was zero.

This means that 14 ÷ 2 = 7.

## Remainders

A remainder is a number that is left over from a division.

Every even number is divisible by 2 exactly. This means that there will be no remainders.

When dividing an odd number by 2, there will always be a remainder of 1. For example:

There are 7 stars. To divide them by two, we can sort them into groups of 2:

There is one star that could not be put into a group of 2.

This means that 7 ÷ 2 = 3 remainder 1 (3 r 1).

## Dividing by 2 in the National Curriculum

In Year 1, pupils should be taught to:

• solve one-step problems involving multiplication and division, by calculating the answer using concrete objects, pictorial representations and arrays with the support of the teacher

The notes and guidance suggest:

Through grouping and sharing small quantities, pupils begin to understand: multiplication and division; doubling numbers and quantities; and finding simple fractions of objects, numbers and quantities.

In Year 2, pupils should be taught to:

• recall and use multiplication and division facts for the 2, 5 and 10 multiplication tables, including recognising odd and even numbers
• calculate mathematical statements for multiplication and division within the multiplication tables and write them using the multiplication (×), division (÷) and equals (=) signs
• show that multiplication of two numbers can be done in any order (commutative) and division of one number by another cannot
• solve problems involving multiplication and division, using materials, arrays, repeated addition, mental methods, and multiplication and division facts, including problems in contexts.