It would be quite easy to find 0.6 on a number line. It's only 6/10. It's made up of six tenths.
Now √5 is equal to 2.236067977........ to infinitum.
It's made up of many little and random fractions; to a certain degree infinitely many little and random fractions.
This means that you'd never be able to find its precise value on a number line. You could zoom in to that line for eternity and never find the precise value of √5. You'd think you're getting closer to it's precise value - but it slips away and you just can't reach it.
...Welcome to the asymptotic realm of mathematics. You've been pixelated, digitized and spaghettified. Life will never be the same again.