Question 803135
RATIOnal numbers are all numbers that can be expressed as a RATIO of integers.
That includes integers and fractions, such as {{{3=3/1}}}, {{{-2=(-2)/1}}}, {{{1/2}}} and {{{-3/7}}}.
Some rational numbers can be expressed as "terminating" decimals like {{{1/8=0.125}}}.
Other rationals, turn into decimals with an infinite number of repeating digits, like {{{1/11=0.09090909}}}{{{"....."}}}.
 
The irrational numbers do not include numbers like {{{pi}}} or {{{sqrt(2)}}}. Those are called irrational numbers.
Irrational numbers cannot be written as fractions, and the digits in their decimal approximations do not repeat, ever.
 
Irrational numbers are real numbers, just like the rational numbers.
After all, the length of the diagonal of a square with side length 1 is {{{sqrt(2)}}}.
However, they are a pain to work with in math class.
For practical purposes we use approximations like {{{3.14}}} for {{{pi}}} and {{{1.42}}} for {{{sqrt(2)}}}.
 
Sometimes teachers will try to trick you and ask you about expressions, like
{{{sqrt(4)}}},  that look like they would be irrational, but
{{{sqrt(4)=2}}} is an integer, and all integers are part of the rational numbers.
Stay alert. Don't let them trick you. Those are rational numbers in disguise.