That sounds really complicated. Someone should invent something to do all that without all of those laborious manual calculations. A calcu... No! I've got it! A computer!!! /s [:p]

It does sound complicated when you have to write it down but once you do it a few times it becomes second nature and you can do it almost automatically. It's not like you can't move a few more centimeters if you got it wrong the first time [:)]