Simple application for window users . Build using AWT(Abstract Window Tool). Through AWT we can build all the window application. It is easy to understand as only buttons and textarea is used to create this aplication. Anyone can understand this easily as no additional functionality or complicated attribute are added in this. You just need JDK(java development kit) means you just need java environment and an IDE like eclipse to run this code . This calculator works similar to the normal calculator. And it works fine.