I can do it, and somewhat easily, it's just figuring out exactly what I'm supposed to do that's the hard part, and trying to keep track of all the figures. Provided I can do it vertically, anyway. Multiplication and division are much harder, and I often have to resort to a calculator. I know you didn't intend it as a slight, hence the smiley and attempted joke. I rarely work with vague numbers because that's much harder; if I don't have a firm grasp of the number I can't manipulate it as easily.