A rational number is defined as number of
the form a/b where a and b are integers and b is not equal
to 0.

A rational number is a number that can be
expressed in the form a/b, where a and b are integers and
b ≠0.

Example:

0, 1/2, and -41 are rational numbers.

Each rational number corresponds to a unique
point on the number line (but most points on the number line
do not correspond to a rational number -- they correspond
to an irrational number).