It's common to ask for a specific type change. For example, you might hand a five dollar bill to someone and ask "Do you have five singles?" ("Singles" are one dollar bills.) Sometimes by briefly explaining why you need the change ("Can you break a five for me? I need coins for the parking meter"), the other person automatically knows what type of change to give you. In most cases, if you ask for change, the other person will inquire as to what you need.