Galculator weird behavior

Why does galculator miscalculate 4000225165312/512 and gets 781293977.6? **Note** This is intended as a **canonical question** cautioning against the unreflected use of galculator 1.2.4. * Please do not use it. Here (1) (2) (3) are some good reasons why. * I've already uninstalled it because I was ashamed by "my" calculations today. I've replaced it with mate-calc which computes all of these expressions properly.