A rational number is a number that can be represented as a fraction of two integers.

$\frac{a}{b}$ is a rational number if a and b are integers.

Since b in $\frac{a}{b}$ can be equal to one, all integers are rational numbers. For example, 4 can be represented as $\frac{4}{1}$. Therefore 4 is an integer but it is also a rational number.

If you write a rational number as a decimal, it can either be a decimal that ends at some point or a decimal that keeps repeating a sequence of digits.

• A decimal that ends at some point:

  • $\frac{1}{2} = 0.5$

  • $\frac{6}{19} = 0.3157894737$

• A decimal that keeps repeating a sequence of digits:

  • $\frac{2}{11} = 0.1818181818... = 0.\overline{18}$

  • $\frac{41}{333} = 0.123123123... = 0.\overline{123}$

  • $\frac{1}{3} = 0.33333333... = 0.\overline{3}$

  • Notice that you can use a dash above a repeating sequence of digits to show that this is a repeating pattern. This way it is easier than writing these types of numbers.