Understanding negative numbers

We can easily understand the concept of negative numbers through the Number Line. Let's take a look at SMP Figure 001 below:

The point "0" in the number line is referred to as the origin. Every point to the right of 0 is associated with a positive number and every point to the left of 0 with a negative number. This convention indicates that every number is associated with a directed distance from the origin. The negative numbers are preceded by the negative (-) sign and the positive numbers may or may not be preceded by the (+) sign.

Mathematical operation with negative numbers:

As an exercise problem let's solve -2 + 5 by using the number line in SMP Figure 002 below:

Solution: Starting from the origin 0, we can count  2 units to the left (representing the negative 2 value); then   from point -2 we move right 5 units (noting 5 as positive). This simple method helps us to quickly arrive at the answer which is +3 units.