"Do you have 84¢ I can have"

I was on the train this morning and a homeless guy asked me do I have 84¢ he can have. I’m not making fun of homeless people, but why do they ask for odd amount of change…Why not ask for 50¢ or $1?? Sometimes they will get bold with you. One day, one asked me for $5….. I’ll give them a dollar or some change, but when they say something like that, it throws me off.