The Windows Calculator is a nifty tool designed for doing all kinds of quick calculations. Windows Calculator is not like the calculator in the previous versions of Windows. It has many modes like standard, scientific, programmer and statistics.
There are many ways you can open the Calculator. You can open the Calculator from Start → All Programs → Accessories → Calculator. You can also press the key combination Windows logo key + R to open the Run dialog, type calc and press the Enter key to run the Calculator.
When you first open the calculator, the standard, basic Calculator window appears as shown. With the Calculator in standard mode and with the basic configuration, you can do simple mathematical operations by entering the values to be computed separated by the operator (+ for addition,