Real numbers are all the numbers that can be found on the number line. They include rational and irrational numbers. You know what a rational number is now. But what are irrational numbers? Irrational numbers are numbers whose digits go on forever and never repeat. They cannot be written as a ratio of an integer to a non-zero integer. It might seem like irrational numbers are rare, but they aren’t. There are an infinite number of irrational numbers. In fact, between any two rational numbers, there an infinite number of irrational numbers!

Which of these numbers is irrational?

A
0.62636465646361

B
0.050.05, which is equal to \frac{1}{20}
20

1


C
\sqrt{8}√
8

, which cannot be expressed as a fraction

D
\frac{2}{9}
2/9
, which as a decimal has one digit that repeats indefinitely