How can I tell a rational and irrational number apart?

1 Answer
Gió
May 27, 2015

Well, an irrational number such as piπ has an oo∞ number of digits after the point and they do not present a recognizable pattern.
A rational number (the result of dividing two integer numbers) either stops after some digits or has oo∞ digits but following a pattern (repetitions for example).
Examples:
Rationals:
5=5/15=51
1/2=0.512=0.5
2/3=0.6666666666.... always the same number after the point!
6/11=0.5454545454... always the same pattern of repeating 54!

An irrational number doesn't follow a pattern after the point, the decimal goes on forever without repeating. Remember that you cannot write your irrational as a fraction of two integers.

You can have "important" irrational numbers as pi oe e or the result of square roots as sqrt(2)=1.414213562.....

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