Here are the rules when two signs are next to one another:

From these rules, we can see that two signs of the same result in addition; this is the case for + + and - -. Also, opposite signs result in subtraction; this was the case for - + and + -.

Let’s have a few examples.

Let’s have a few examples.

**Example 1**

Complete the calculation:

We are taking away a negative number, which means that we are adding 3.

The answer to this question is 11.

**Example 2**

Complete the calculation:

We are adding a negative number. Opposite signs result in a negative sign. The calculation becomes:

The answer is 15.

**Example 3**

Complete the calculation:

We are adding a positive and we know that signs that are the same become a positive. Therefore, the calculation becomes:

Therefore, the answer to this question is 78.

**Example 4**

Complete the calculation:

We are taking a positive and as the signs are opposite, it results in a negative. The calculation is:

The start number is a negative (-24). Therefore, it is probably best to sketch a quick number line with -24 on it. My sketch is given below.

We are taking 4 away, which means that we are moving 4 towards the left.

The answer for this calculation is -28.

**End Note**

The key rules to remember from this section is that:

- Two of the same signs result in addition; this is the case for + + and - -
- Opposite signs result in subtraction; this was the case for - + and + -

It is worth getting these rules down on a revision card.