A question from Joshua Yew:
Is 0 a rational number?
A number is a rational number if we can expressed it as a fraction a/b where a and b are integers and b is not zero.
Let's look at zero - it is a result from fractions like 0/5, 0/89 ?
In other words, Zero can be expressed a fraction such that the numerator is an integer and the denominator is an integer that is not zero.
Hence 0 is a rational number.