Finding if Decimal Number is rational or irrational

Last updated at August 13, 2026 by

Let us find if decimal numbers are rational or irrational

Finding if Decimal Number is rational or irrational.jpg

Let us look at some examples

 

Q: Is 2.5 a rational number?

-a-

Since 2.5 has a terminating expansion

So, it is a rational number.

-ea-

 

Q: Is 0.142857142… a rational number?

-a-

0.142857142… = 0.1428571428570142857…

Since the terminal expansion is non- terminating repeating.

It is a rational number.

-ea-

 

Q: Is 1.10100100010000.. a rational number?

-a-

1.10100100010000..

Since the terminal expansion is non- terminating non-repeating.

It is an irrational number.

-ea-

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