When I was a kid my grandmother offered, in one hand, a five dollar bill, and three singles in the other. I took the three singles, and grandma thought it was the most hilarious thing ever. She then corrected me and explained how a five dollar bill was worth more than three one dollar bills, even though the three one dollar bills looked like more because they were separate bills. A few weeks later she offered me the same thing, a set of five dollar bills and three singles. I took the singles.