Using the Calculator's features

The following sections explain the Calculator's features in more detail.

Simple arithmetic

Here are some simple problems you can enter on the Calculator.

5 * 4 =
100 + 4 + 6 + 7 - 3 / 2 =
1000 / 5 / 10 / 30 =
1.25 + 3.85 / 1.7 =

Type the numbers and arithmetic symbols on your keyboard. Remember to press = or <Enter> to finish each problem. When you begin a new problem, the total from the last one clears from the display automatically.

Scrolling the tape

Enter several long calculations, until the earliest ones have moved up the tape and off the top of the calculator. Now press the <Up Arrow> key repeatedly to ``rewind'' the tape. The earlier calculations reappear.

Use the <Down Arrow> key for the opposite effect, to advance the tape back to more recent calculations.

To move through the tape more quickly, use <Ctrl>U and <Ctrl>D to rewind and advance the tape five lines at a time; <PgUp> and <PgDn> to rewind and advance the tape ten lines at a time.

If you want to rewind the tape all the way, press <Home> or <Ctrl>T. Pressing <End> does the opposite: it advances the tape to the last calculation entered.

With the tape still ``rewound,'' enter a new calculation and see what happens: the tape automatically advances itself to the end of the most recent calculation, just as if you had pressed <End>.

The figures on this tape are kept only while the Calculator is on. When you turn off the calculator, the figures disappear permanently.

The Calculator only remembers the previous 100 calculations on the tape. You cannot view any calculations previous to the first on the tape.

Storing numbers in memory

You can store up to four numbers in the Calculator's memory for later use. For example, you may want to use the results of a calculation in several others. Rather than re-entering the figure for each calculation, store the figure in memory and recall it as you need it.

Storing a number

The number you want to store must be on the Calculator's display, as either the answer to the previous calculation or simply a number you typed in. Follow this procedure:

1. Enter the following calculation: 5+63-34=

   The result is 120.

2. Press s (Sto).

   The Store box holds four different fields: A, B, C, and D. The first field, A, is already highlighted. Each field can hold one number. Press <Enter> to store 120 in field A.

3. After a short delay, the Calculator screen returns to normal.

Using a stored number

Now that you have stored a number, suppose that you want to use it in a problem. For example, 104 / 4 stored_number. Follow this procedure:

1. Enter 104/4 in the calculator. After you enter the ``'' symbol, press r (Rcl).

   The Recall box shows the number currently stored in memory. Press <Enter> to recall it. (If there are several numbers in the recall box, use the arrow keys to highlight the one you want to recall.)

2. The Recall box disappears at once. The stored number is now in the display window, just as if you had entered it by hand. Enter = to complete the calculation. Your answer is 3120.

   The number you retrieved is still in memory, and it stays there until you replace it with another one or turn off the Calculator.

Negative numbers

To enter a negative number, type the number followed by an n. The number is now preceded by a minus sign on both the display and the tape. It behaves as a negative number in all calculations. Pressing n also removes a minus sign if the displayed value already has one.

For example, type 5 5n = to multiply 5 by negative 5. The result is -25.

Percentages

You may sometimes perform calculations whose operands include both a number and a percentage of that same number. The Calculator's percentage key lets you do this without calculating the percentage separately.

Suppose that you make a $25.00 purchase and want to calculate the total price when six percent sales tax is included. You enter 25 + 6 % and the result is 26.5, or $26.50. Note that you do not need to press =.

If you enter the wrong number

If you enter the wrong number in the middle of a problem, type c to clear the number and enter a new one. For example, if you want to multiply 7 by 7, but enter 7 times 6, type the following, 7 6 c 7 and the mistake is corrected.

The <Bksp> key also helps you to correct mistakes. If you want to change or erase the number you just typed, press <Bksp> repeatedly to make the number disappear one digit at a time.

Exiting the Calculator

To turn off the Calculator, press o, or <Esc>. You then return to the program you called the Calculator from.

All the numbers stored in memory or on the tape now disappear, just as on a real pocket calculator.

As with all open programs, you must call up and quit the Calculator when you finish work for the day before logging off your computer.