To get to the calculator built into Windows. Click on Start - All Programs - Accessories. Then choose Calculator. A small calculator will pop up. You can use your mouse to click the numbers and functions or you can use the numbers and/or number pad on your keyboard. To use the numeric keypad to type numbers and operators, be sure to press the NUM LOCK key first.

The Windows calculator works like a regular handheld calculator for addition, subtraction, and other mathematical functions. It even has functions like logarithms and factorials that are found in scientific calculators.

If you think you will use the Calculator often, when you see it on the list in the Accessories you can right-click it and choose Send To. Then choose To Desktop (create shortcut).

Remember that the calculator is a Window. So if you are using the calculator and click on another document or file, that calculator window will still be open, but may be beneath the other Window.