### Become an OU student

Succeed with maths: part 1

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

# 3 Addition and subtraction on the number line

Watch the video below to see how you can use a number line to help you with addition and subtraction involving negative numbers.

Interactive feature not available in single page view (see it in standard view).

See how you get on in this next activity.

## Activity 3 Working with negative numbers

Timing: Allow approximately 10 minutes

Try the following examples. Start by drawing your own number line from –10 to + 10.

• a.3 − 7

• a.Start at 3, move 7 units to the left.
Figure 7 Number line for Activity 3, part (a)

Thus, 3 − 7 = –4.

• b.(–2) + 5

• b.Start at –2, move 5 units to the right.
Figure 8 Number line for Activity 3, part (b)

Thus, (–2) + 5 = 3.

• c.(–3) − 6

• c.Start at –3, move 6 units to the left.
Figure 9 Number line for Activity 3, part (c)

Thus, (–3) − 6 = –9.

• d.(–4) + 2