Pi is an irrational number. A rational number is one that can be expressed as a fraction (or ratio), e.g. 1/3. There are fractions that are near Pi, for example: 22/7 = â¦ 3.142857 (PI = 3.14159265...) A closer fraction is: 355/113 = 3.14159292 However whatever fraction you have, you will never get exactly PI.i is an irrational number. A rational number is one that can be expressed as a fraction (or ratio), e.g. 1/3. There are fractions that are near Pi, for example: 22/7 = â¦ 3.142857 (PI = 3.14159265...) A closer fraction is: 355/113 = 3.14159292 However whatever fraction you have, you will never get exactly PI.