My calculator is so special because it is first thing I've written in visual c++. I have done few things in bloodshed c++ but nothing in this MS. I am more of a Pascal guy myself. What makes it more special is the fact that it is written in Bosnia (yes we have computers here, believe it or not) :) I think that it is special also because the textbox is not the main control in which I store the expression and later work on it. The expression is being worked on the moment you click the first button and textbox is there only for display purpose (and because, as I understand, you require it). So, basically calculations are done as soon as you select a number. That might be the one fact that is different from the others. I really do not know what to say about it, because it speaks for itself ;) Download it and see.