How to Add and Subtract Integers by Number-line

Let’s understand it with an example.

Example 1: Work out using number-line

-3 + 4

Solution:

Divide -3 + 4 into three parts

-3 is the integer from where you start.

+ shows jump to right-hand side

4 is the number of jumps

Now lets apply this

You can see on number-line, we start from -3 and on right-hand side take four jumps. So, the answer is 1.

-3 + 4 = 1

Example 2: Work out using number-line

3 – 5

Solution:

Divide 3 – 5 into three parts

3 is the integer from where you start.

– shows jump to left-hand side

5 is the number of jumps

Now lets apply this

You can see on number-line, we start from 3 and on left-hand side take five jumps.

So, the answer is -2

3 – 5 = – 2

Remember:

a) For +

jump to right-hand side

b) For –

jump to left-hand side

TIP: For the questions like – 5 + – 4 its easy to first reduce the two operators/signs in the middle to ONE, then find answer by number-line.

Remember,

(a) Same both operators/signs reduces to +

That is,

++ reduces to +

– – also reduces to +

(b) Different both operators/signs reduces to –

That is,

+ – reduces to –

– + also reduces to –

Leave a Reply Cancel reply