# Negative numbers

Concept

Negative numbers are any numbers that is smaller than zero. To signify a negative number, we simply place a negative sign in front of a positive number. We shall use the number line to illustrate and explain negative numbers.

From the diagram, we can easily see that negative numbers are the numbers that is small than zero and its range is indicated by the arrow. Zero is not seen as a positive or negative number.

## Positive and Negative Numbers Multiplication

Let's learn what happens when we multiply positive and negative numbers together.

If both numbers are positive or negative, then the product will be positive. In the other situation where one number is positive and the other is negative, the product will be negative. We have tabulated the table below to help you understand the concept of multiplication of positive and negative numbers easily.

 Numbers +ve -ve +ve +ve -ve -ve -ve +ve

Examples

2 x 5 = 10

2 x -5 = -10

-2 x -5 = 10

What happens if we want to multiply more than 2 positive and negative numbers?

First we have to count the number of negative signs in the function. If the number of negative signs is even (2, 4 etc...), we can determine that the product is positive. On the other hand, if the number of negative signs is odd (1, 3 etc...), the product would be negative.

Let's try out positive and negative numbers multiplication for more than 2 numbers.

2 x -5 x 2 x – 1 x -3

First, we count the number of negative signs in the term. There are 3 (odd) thus the product has to be negative.

Then we multiply the numbers as if the negative signs are not there.

2 x 5 x 2 x 1 x 3 = 60

Then we add the negative sign to the result. The answer is – 60.

'Try it Yourself' Section

Try multiplying positive and negative numbers as well.

a) - 3 x 2 x 2 x 4 x -5