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-

  1. Chapter 1 Class 9 Number Systems
  2. Concept wise

About the Author

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 10 years. He provides courses for Maths and Science at Teachoo.