what is an irrational number and a rational number?

2 answers

An Irrational Number is a real number that cannot be written as a simple fraction
A rational number is a number that can be written as a simple fraction
any rational number can be written as a terminating decimal lor a repeating decimal

1/5 = 0.2000000
17/8 = 2.12500000

1/3 = 0.33333333...
9/7 = 1.28357142835714...

anything else is irrational

1.0203040506070809010011012... is irrational
pi = 3.14159265... is irrational
√2 = 1.414213562... is irrational