#
Calculator Basics

As you would expect, you use the calculator just as you would a real
pocket calculator. Just as with a conventional calculator, space is at
a premium, so many of the calculator buttons have to double up the functions
they provide. The layout of the calculator in its normal state has the
functions you would expect to see on a fairly standard scientific calculator,
which means that it is probably self explanatory. Notice the **shift**
button in the top left hand corner.

Enter numbers either by clicking on the buttons or using the keyboard
(note: to use a numeric keypad make sure Num Lock is on). To enter a number
in exponential format, enter the mantissa, followed by the **EXP** key,
then **+/-** if required, then the exponent. To use the arithmetic functions,
click their buttons. If the function is unary (i.e. acts on one number,
e.g. **1/x**) the display is updated to the result. If the function
is binary (e.g. **+**, **-**, **X** etc.) enter the second number
and click **=** or another arithmetic key.

The functions of the buttons in their shifted state are not marked on
the calculator body, but the buttons change when you press the **shift**
button. If you press the **shift** button again, the buttons revert
to their un-shifted state.

Most of the calculator buttons can be accessed from your computer keyboard
(these are sometimes called 'keyboard shortcuts' or 'keyboard accelerators').
Keyboard accelerators are listed by key and
by meaning. You can also use the Caps Lock key
on your keyboard instead of the **shift** button.

An optional menu bar (or command bar) can be used to give access to
additional functions. All the menu bar functions can be obtained in other
ways. Activate the menu bar using the Layout tab
of the Options dialog.

##
- All Clear

Clears the calculator, and resets any functions. The contents of the memory
are not affected by

**AC**. The memory can be cleared after pressing

**AC**
by pressing

**Min**.

##
- Clear Entry

Erases the last number or operation entered.

##
- Addition

This button performs addition.

##
- Minus

This button performs subtraction.

##
- Divide

This button performs division.

##
- Multiply

This button performs multiplication.

##
- Equals

Displays the result of an arithmetic operation. It can be used during a
calculation to ensure that an intermediate result has been evaluated. Unless
the

**=** button is pressed, it is possible that an operation is incomplete
- pressing

**=** ensures that no arithmetic operations are pending.

Certain functions make use of the **=** button to signify the end
of input, in order to evaluate a result.

##
- Percent key

This button (

or Enter button) displays the result of an arithmetic operation as a percentage.

Examples:

Calculate five sixteenths as a percentage.

**5 / 1 6 shift %**

Result: 31.25%

Calculate 17.5% of £
250.00:

**250 x 17.5 shift %**

Result: £
43.75

Calculate 12% mark-up on $250

**250 + 12 shift %**

Result: $280

Give 5% discount on goods costing $125

**125 - 5 shift %**

Result: $118.75

##
- Pi key

This button (shifted Exp button) displays the value of pi (the ratio of
the circumference of a circle to its diameter).

##
- Memory Plus

Pressing this button adds the number displayed to the contents of the memory.
Additional memories can be accessed by pressing the

**shift** key before
pressing this button, which will change to

**Mn+**.

##
- Memory n
Plus

Add to one of ten memories (labelled 0-9) using this button, which is obtained
by pressing the

**shift** button. After pressing

**Mn+** press the
number button corresponding to the desired memory. Memory number zero is
the default memory (i.e. the memory referred to by the un-shifted memory
buttons).

##
- Memory Input

Press the

**min** button to enter the currently displayed number into
the memory.

If you first press **shift** before **Min** you can select one
of the ten memories (0-9). Memory zero is the default memory, i.e. the
memory available without pressing the **shift** button.

##
- Memory n Input

Input a value to one of ten memories (labelled 0-9) using this button,
which is obtained by pressing the

**shift** button. After pressing

**MnIn**
press the number button corresponding to the desired memory. Memory number
zero is the default memory (i.e. the memory referred to by the un-shifted
memory buttons). The "Clear All" button allows you to delete the contents of all
the memories.

##
- Memory Recall

Use this button to put the contents of the memory onto the display. The
default memory is number zero. To display other memories, first press the

**shift** button and then the

**MR** button and select the required
memory.

##
- Memory n Recall

Access one of ten memories (labelled 0-9) using the this button, which
is obtained by pressing the

**shift** button. After pressing

**MnR**
press the number button corresponding to the desired memory. Memory number
zero is the default memory (i.e. the memory referred to by the un-shifted
memory buttons).

##
- Decimal Point

Use the

**point** button to enter the decimal part of a number. The
decimal point is disabled in non-decimal number systems.

##
- Exponent

Use this button to enter a number in exponential form.

Example:

To enter the number 1.234 x 10^6 (1.234E6) press the following buttons:

**1 . 2 3 4 EXP 6**

##
- Number buttons

Number buttons are used in all modes. In Hexadecimal mode they are augmented
by the letters A to F. In Octal mode the 8 and 9 buttons are disabled.
In Binary mode only the numbers 0 and 1 are enabled. In

*statistics mode*
the number buttons are used with the

**shift** button to obtain the
statistical functions.

##
- Shift

Use to access additional functions. The functions available depend on the
calculator mode, and are indicated by changes to the legends on the calculator
buttons.

##
Errors

If you get an error, the calculator display will contain an appropriate
message, and possibly some further descriptive information. In the case
of certain errors, the calculator functions are disabled and you need to
press the

**AC** button to clear the error.