Answer:
A rational number is a number that can be written as a fraction. Any number that can be written as a fraction can be written as a decimal, and some rational numbers can be converted to repeating decimals. To convert a fraction into a decimal we must divide the numerator by the denominator here is a quick example...

As you can see, 5/6 written as a decimal is 0.83333(repeating).
I hope this helps.