An integer is a special set of numbers which consist of zero,
positive numbers and negative numbers excluding fractions. For example,
-2,-1, 0, 1, 2, etc… Numbers with a minus (-) sign are called negative
numbers. When a number is written without any sign, it is considered
positive, except 0. Zero is neither a positive number nor a negative
number. When two integers are at same distance from origin but only if
they are in opposite directions, then they are called opposite numbers;
for example, opposite of 9 is -9 and vice versa. 0 is the opposite of
A number line is a reference for comparing and ordering numbers.
Every number on number line is plotted with respect to origin (zero) and
the position of a number on a number line determines the value of that
number. This implies that any number right to zero is always greater
than zero and that numbers left to zero are less than zero.