Addition and Subtraction

Positive and Negative Numbers

Positive numbers are the numbers that you use every day. Examples of positive numbers are the amount in your bank account when you have some money to spend, or the temperature that the weather forecaster gives you on the news on a hot day. 

Sometimes situations give rise to negative numbers. This is when you are overdrawn in your bank account, or when the temperature drops below freezing.

You can represent both positive and negative numbers on a number line.  The numbers to the left of zero are negative. The numbers to the right of zero are positive.

Use the arrows to view the examples and practice questions, or click the link below to download a printable file. 

Example 1: Addition

You can represent both positive and negative numbers on a number line. When you are adding you move to the right. 

Use a number line to work out 2 + 5

Start at 2, and because you are adding count five spaces to the right. You should end at 7. 

2 + 5 = 7 

Practice Question 1

Work out 1 + 8 using a number line. 

Practice Question 1 Answer

Example 2: Addition

Use a number line to work out -3 + 5. 

Start at -3 and because you are adding count five spaces to the right. You should end at 2. 

-3 + 5 = 2

Practice Question 2

Practice Question 2 Answer

Example 3: Subtraction

When you are subtracting positive numbers using a number line, you move to the left.

Use a number line to work out 2 - 5. 

Start at 2 and because you are subtracting, count five spaces to the left. You should end at -3. 

2 - 5 = -3

Practice Question 3

Work out 1 - 8 using a number line.

Practice Question 3 Answer

Example 4: Subtraction

Use a number line to work out -3 - 5. 

Start at -3 and because you are subtracting, count five spaces to the left. You should end at -8. 

-3 - 5 = -8

Practice Question 4

Work out -1 - 4 using a number line. 

Practice Question 4 Answer

Example 5: Subtracting Negative Numbers

When you are subtracting negative numbers using a number line, the negatives cancel out to make a positive. 

Use a number line to work out 2 - -5.

Here there are two minus signs together. When they combine they make a positive.

So 2 - -5 = 2 + 5. 

Start at 2, and because you are subtracting a negative (which is the same as adding a positive) count five spaces to the right. You should end at 7. 

2 - -5 = 2+5

       = 7  

Practice Question 5

Work out 1 - -8 using a number line. 

Practice Question 5 Answer

Example 6: Subtracting Negative Numbers

Use a number line to work out -5 - -4. 

Start at -5 and because you are subtracting a negative number, count four spaces to the right. You should end at -1. 

-5 - -4 = -5 + 4 

    = -1

Practice Question 6

Work out -1 - -4 using a number line. 

Practice Question 6 Answer