## What is rational numbers?

The rational numbers Q are the fraction field of the ring Z of integers. In more elementary

terms, a rational number is a quotient a/b of two integers a , b and b is not equal to zero.

Or we can say that, the rational number is the ratio between the two integers a and b.

Where b is not zero

### Example:

**2.4 is a rational number because 2.4= 12/5 (12 and 5 are both integers)**

Here are some others examples which is given below:

Number | As a Fraction | Rational? |
---|---|---|

5 | 5/1 | Yes |

1.75 | 7/4 | Yes |

.002 | 1/2000 | Yes |

−0.1 | −1/10 | Yes |

0.111… | 1/9 | Yes |

√5 (square root of 2) |
? | NO ! |

Oops! The square root of 5 cannot be form as a simple fraction! And there are lots of like this type of numbers, and because they are not rational numbers. These numbers are called Irrational.

Other famous irrational number is Pi (π):

**pi(π )= 3.14159265358…**