Why do people crumble bills before they give them to cashiers?

Some people just like to be rude and nothing else. Others may be doing it as a joke, but it is still rude.

why do you correct peoples spelling when you should really stick to the question? I speak 5 languages and English was the very last one I learned on my own. How many languages do you speak? Do you speak 5? If not than according to you, you must be stupid and therefore insecure about your own limited knowledge. Shallow is what I call people like you.

to make sure that they're not accidentally giving too much money; sometimes fresh bills stick together

i do it because new bills tend to stick to each other and this way i know im giving the exact amount