### Theory:

A number that can be expressed as \(a / b\), where \(a\) and \(b\) are integers and \(b ≠ 0\) is known as a rational number.

- \(-2/3\)
- \(6/7\)
- \(-3/1\)

Example:

Important!

Any number divided by \(0\) is not a rational number.

- \(4/0\) is not a rational number. Hence it is an undefined number.

If there are \(10\) apples to be divided for \(4\) children, it is not possible to give \(3\) complete apples to each one. But, if we cut \(2\) apples into half, then there will be \(4\) half pieces and \(8\) full apples. So each child would get \(2\) full and \(1\) half piece of apple.