lexipixel - 2:38 am on Mar 23, 2012 (gmt 0)
To keep the rounding errors consistent and manageable, I try replace all division with multiplication, e.g.-
100 / 3 = 33.333...
100 * .3333 = 33.33
It's not perfect, but you can control (or at least know what to expect) from the results.
(FOOTNOTE: This is why grocery stores sell things "3 For $2.00"... instead of trying to figure out exactly how much one costs, they know you'll take the mentally lazy route and just buy three).