Originally I created these for the 2013 World Water Week in Stockholm, to be used with our Integration Trivia Game. Eventually, though, we would use them for many learning events.
I went a little overboard designing these — I got into the details and the symbolism of money, etc. I have to give credit to my colleague Darren Saywell who suggested that they be different colors depending on the amount — like Euros. My American mind made them all one color at first (blue).