Represent -1 on a number line.

Hint: Negative signs are often present on the left of the number line assuming that 0 is in the center. The above mentioned number can be easily spotted on a real,rational or an integer number line.

Complete Step by Step Solution:
A number on a number line is first represented by the length of a line segment, that is, by the distance from the origin ZERO to the point. Then the endpoint of the line segment is used to represent the number, instead of the length. As -1 is a negative integer it will be on the left side of the number line(taking 0 as origin). Lets try to locate -1 on an integer number line.

As it is shown in the above figure the point marked with a red circle is -1. i.e., a unit distance left from the origin.

Note: The numbers on the right hand side of the origin are always positive and that on the left hand side is always negative; while drawing the integer number line do keep in mind that all numbers are equally distributed i.e., the distance between two numbers will always be the same.