The standard arithmetic calculator functions almost exactly like an inexpensive pocket calculator, except that you don't have to fumble around looking for it on your desk.
If you make a mistake while entering a number, press Backspace or click the Backspace button. This will erase the last digit from the display; you can continue erasing a character at a time until you correct the error.
To clear the last entry in a sequence of numbers and arithmetic symbols, press Delete or click CE (clear entry). For example, if you're adding up a list of numbers and you make a mistake, simply click the CE button and reenter the last number; you don't have to start over.
To clear the current calculation entirely and return the display to a 0, press Esc or click C.
The heart of Calculator's standard window is the ten-key pad. To the right and below the pad are all the basic arithmetic operators. Note that for division, you use the slash button (/), and for multiplication, you use the asterisk (*).
The sqrt button produces the square root of whatever number is in the display. To get the square root of 796.5, for example, enter 796.5 and click sqrt. You don't have to click the = button.
The % button lets you figure percentages. Let's say you wanted to figure the 8.75 percent sales tax on a $56.50 purchase. You would do the following:
Your sales tax will be 4.94375, or $4.94.
The 1/x button produces the reciprocal of whatever number Calculator is currently displaying. Entering 10 and then clicking 1/x, for example, will give you 0.1.
The +/- button changes the sign of the number currently on display. The typical use for this button is to enter a negative number in the middle of an arithmetic operation. For example, to multiply 52 times -23, you would:
You'll get the result -1196.
Note that if you enter 52, click the multiplication button, and then enter -23 followed by =, you get a different result. Calculator treats the minus sign as a replacement for the multiplication operator and simply subtracts 23 from 52.