The calculator that is... This is a problem I deal with successfully on a periodic basis on the job. Just for you peeps I will keep it as simple as possible without making it rediculous. Your calculator has just died. You've got a cylindrical part 1/2 an inch thick (12.7 mm if you just have to have metric). You've got to drill 3 holes though it, from top to bottom. The holes are 1/4 inch (roughly 6.35 mm if you just have to complicate your life) in diameter and laid out equally spaced on a 3 inch (76.2mm) circle. The machine you are using has an attachment that gives you an x,y coordinate system. It does not do calculation involving division by numbers other than 2 or any other calculations at all. After securing the part in the vise mounted on the machine and finding the center point of the top surface which we shall now call 0,0 give me the coordinate locations of the three holes you need to drill. Or at least tell me how you'd go about finding said coordinates. Remember no calculators oh and you don't have any trig tables either. YOur hole location tolerance is plus or minus .01.