What is irrational?

A number is irrational when it can’t be written as a simple fraction, like 3/2 or 5/4, and it keeps going forever without repeating.

Imagine you have a ruler that measures exactly 1 foot long. Now imagine a special kind of number that tells you the length of the diagonal of a perfect square with sides equal to 1 foot. That number is called sqrt(2), or the square root of 2, and it's irrational.

If we tried to write sqrt(2) as a fraction, like 7/5 or 14/10, we’d be wrong. It doesn’t end, it just keeps going on and on with no pattern, like the never-ending story of your favorite bedtime tale.

You can think of it like this: if you had a box that kept giving you new digits forever, and they didn’t repeat in any way, that’s an irrational number. It's not magic; it just doesn't follow the rules of regular fractions or simple patterns.

Some other famous irrational numbers are pi (π), which helps us find the circumference of a circle, and e, used in math to describe growth and decay, both go on forever without repeating!