My wife is half Scottish and half French Canadian so she tends to throw nickels around like manhole covers. I stopped going down the paper products aisle with her and it gives me an extra ten minutes to check out more interesting products that might actually be a good deal while she calculates down to the tenth of a penny just how much we are paying per sheet.
I once asked her if all of the sheets were the same size and it screwed up her calculations for several days until she confirmed on the internet that sheets were of a standard dimension, at least until I had her compare two different products and they were not quite, exactly the same. I have an evil twin that comes out when I am in the paper products aisle.