Question

How do you evaluate `-2.4- 4.8`?

Answer 1

See below: answer `-7.2`

Explanation:

First you need to know the rules:
1. When you are multiplying with two negative signs the answer will always be positive.
2. When you are multiplying with two positive signs you will get positive answer.
3. When you are multiplying with different signs you will get a negative answer.

However, in this case we are ADDING two negatives.

So:
`(-2.4)` is negative and you will have to subtract `4.8` from this number. To do this you need to use the negative scale
e.g So if you go from `-2` and go to the left 4 numbers because that is what is asking you to do, then you will get down to `-6` .
This is the same you have to do with your question with the decimals

`(-2.4) + (-4.8)`

`= -7.2`

To check your answer you can type it in the calculator.

Using the positive/negative button - type in -2.4 - 4.8 and you will get `-7.2`

Hope this helps

Answer 2

`(-2.4)+(-4.8) = -7.2`

Explanation:

Compare `+2.4 +4.8 and -2.4 -4.8`

They both represent an addition.
However, the first is the addition of positive numbers which means moving to the right, UP the number line.

`(+2.4)+(+4.8) = +7.2`

The second is the addition of negative numbers which means moving to the left, DOWN the number line.

`(-2.4)+(-4.8) = -7.2`

Adding positive and negative numbers can be summarised as:

If the signs are the SAME: keep the sign and find the sum (add).

If the signs are DIFFERENT: keep the sign of the bigger number and subtract.