Rational number is
any number that
can be expressed as the quotient or fraction p/q of two integers, p and q, with the denominator, q, not equal to zero
The history of rational numbers goes
way back to the beginning of historical times. It is believed that knowledge of
rational number precedes history but no evidence of this survives today. The
earliest evidence is in the Ancient Egyptian document the Kahun Papyrus.
Ancient Greeks also worked on rational numbers as a part of their number
discovered that not all numbers were rational. For instance, the square root of
two, which is the length of the longer side of a triangle with sides one and
one, is not a rational.
Euclid's elements date to around 300
BC. Indianmathematicians also worked on rational
numbers. This is documented in different texts but the most important is
probably the Sthananga Sutra which dates back to around the second century BCE.