I'm teaching myself C# and so far it's been fairly simple. I've created the standard "hello world" console-based program and a rudimentary console-based calculator. I decided that those were too easy (I have a few years of experience in Java) and figured I'll create a calculator with a GUI. The GUI and button/text box manipulation are all straightforward, but I'm having a bitch of a time getting it to act like Windows Calculator. My requirements: - When you click on an operand, the first number doesn't go away or turn to 0. Example: type in "24" and "*". When you click "*", the "24" doesn't go away until you click on another number. To do this, I have two Decimal variables that update the text box whenever I click on a number. Before pushing the operand, the first decimal dFirst updates the text box and after pushing the operand, the second decimal dSecond updates the text box. Pretty straightforward and my requirement above is satisfied if I code it like this, but putting a decimal point is impossible. For example, I want to multiply 24 by 30. I click "24", "*", and "30". Everything works perfectly. I am happy. Now, I want to multiply 2.4 by 3. I click "2.4", but right after I click "4", the decimal point goes away, leaving me with "24". The reason this is because I'm converting between strings and decimals all the time. While strings can have the value "2.", decimals cannot. Any suggestions?