Note that this help is available from within the calculator, just select Help from the main menu.
The number keys to and decimal point are used to enter numbers. To enter a negative number, press after entering the number.
The key deletes the last digit entered and can be used to correct a number or exponent.
The key clears the display ready for a new calculation.
To enter a number with an exponent, press then enter the exponent using the number and keys. Note that the exponent key means 'times 10 to the power' and it is not necessary to enter the 'times 10' yourself.
For example, to enter 2.5x1012, press:
The key is used to access the secondary function of each key (displayed above the key in orange). While shift is active, 'SHIFT' will be shown on the display. Press again to cancel shift mode.
As an alternative to using shift, the secondary function of each key can also be accessed by holding down the key. This feature can be disabled in Settings.
Throughout this help, functions which require shift to access are shown in orange. The shift key itself is not shown.
Numbers can be formatted on the display using either a point or a comma as the decimal separator. Numbers can also be displayed with digit grouping, using either a comma/point or space to separate groups of digits.
In decimal mode, numbers are displayed in groups of three digits. For binary, hexadecimal or octal mode, numbers are displayed in groups of four digits. These options can be set via the Settings screen.
There are four display modes for calculation results. Use the key to cycle through the modes. The display will show 'FIX', 'SCI', 'ENG' or blank to indicate the current mode.
To set the number of decimal places in FIX mode, or the number of significant digits in SCI or ENG modes, press . This will bring up a dialog to select the number of digits, together with the current value rounded appropriately. When the number of digits selected is less than the maximum available, the display will show the number of digits after the mode indicator e.g. FIX:5 or SCI:8.
The result is displayed as a normal floating point value if possible. If its magnitude is less than 0.0001 or greater than 9,999,999,999 then scientific notation is used (see SCI mode below). The number of decimal places cannot be adjusted in this mode.
FIX mode (fixed decimal point)
The result is displayed after rounding to the number of decimal places selected by . If there is not enough room, the result may be displayed with fewer decimal places.
SCI mode (scientific notation)
The result is displayed in the format A x 10B, with the mantissa (A) rounded to the number of significant digits selected by .
ENG mode (engineering notation)
This is the same as SCI mode, except that the exponent is set to a multiple of 3.
The value used for calculations is the unrounded result stored internally, and not the rounded value shown on the display.
Each time the key is pressed, the calculation result is added to a history list.
The key presents a dialog showing the calculation result history, with the most recent results at the top. Select the required value to enter it into the calculator.
The maximum number of results which are stored can be set via the Settings screen (Menu->Settings). When set to 'Off', the key simply recalls the last result, without showing a dialog.
By default, the values in the history list are unique. If a calculation result is the same as one already in the history list, this value is moved to the top. This behaviour can be changed via the Settings screen.
The history list can be cleared via the options menu.
The main memory has four dedicated function keys:
Whenever a non-zero value is stored in the main memory, the letter 'M' is shown on the display.
The main memory can also be accessed via the and keys (see below).
There are nine additional memories which can be accessed via the and keys. These keys show a dialog with the current values stored in the main memory 'M' and the additional memories '1' to '9'. Select the appropriate value to store or recall the memory value.
The values stored in all the memories can be reset to zero via the options menu.
The current display value can be converted between different units using the key.
For most conversions, an original value of 0.0 will be replaced by 1.0 as a convenience to avoid converting zero to zero. This does not apply to conversions which are not a simple ratio, e.g. temperature.
The unit conversion dialog only displays values in decimal, the current radix mode (BIN, OCT or HEX) is ignored.
These are entered exactly as written:
Operations can be joined together:
Multiplication and division have precedence over addition and subtraction and will be performed first:
The parentheses keys can be used to override the normal precedence:
There is no limit to the number of parentheses which can be entered.
The modulo function calculates the remainder after division. Integer and non-integer numbers are supported. For negative numbers, the result has the same sign as the divisor.
Repeat calculations can be performed without re-entering the value and function key, for example:
20 is now a constant for addition:
Similarly for subtraction, multiplication and division:
For trigonometric functions, angles can be specified in degrees, radians or grads. The key cycles through the angle modes, and the display will show DEG, RAD or GRAD to indicate the current mode.
The key also cycles through the angle modes, but also converts the current value in the display.
For hyperbolic functions press the key before pressing , or . For inverse hyperbolic functions use in combination with . The 'HYP' indicator will appear in the display.
Please note that Fractions and DMS are only available in RealCalc Plus.
Fractions are entered using the key, and can be entered as either mixed or improper fractions. The results of calculations involving fractions will be displayed as fractions where appropriate, reduced to their lowest terms.
The key also converts between mixed fraction, improper fraction and decimal format.
The following restrictions apply to fraction entry and results:
Calculation results which do not meet these restrictions will be converted to decimal.
DMS values are entered using the key, and can be entered as either decimal degrees, whole degrees with decimal minutes, or whole degrees and minutes with decimal seconds.
The key also converts between DMS and decimal format.
The maximum value which can be displayed as DMS is 9999°59'59.99". Calculation results outside this range will be converted to decimal.
These modes are set using the , and keys respectively. The key returns to the normal decimal mode. The current value on the display is converted when switching modes.
Please note that these modes are disabled by default, and can be enabled in the settings.
When in BIN, OCT or HEX modes, calculations are performed on signed integer values up to 12 digits. Non-integer results will be truncated.
Negative values are represented in 2's, 8's or 16's complement notation.
Pressing the key negates the current value on the display:
In BIN, OCT or HEX modes, additional logical operation keys become available:
When in BIN, OCT or HEX modes, the values in the history and memory dialogs are presented in the current mode. Values which cannot be converted to the current mode are shown as 'Error' and cannot be selected.
RPN mode can be enabled via the Settings screen.
In this mode, values are entered first, followed by the function key. Values are pushed onto a stack using the key. Functions take their arguments off the bottom of the stack, and push their result back onto the stack. The depth of the stack is unlimited.
Functions which require a single argument, such as or , simply operate on X and replace it, in the same way as normal mode:
→ X: 25.
Functions which require two arguments, such as or , take X and Y off the stack and put the result back:
→ X: 6.
→ X: 256.
If the stack is empty, i.e. there is no value in the Y register, 'Y?' will be displayed for a short time when trying to do an operation which requires two arguments.
→ X: 3.
Note that as all operations are immediate, there is no need for parentheses or an equals key.
The following additional functions are available in RPN mode:
The display shows the current value at the bottom of the stack, X, and the next value, Y. This can be changed in the settings to show just the X register, or X, Y and Z. The size of the calculator keys is reduced compared to normal mode when showing X/Y or X/Y/Z.
As there is no equals key, the result of every operation is added to the result history.
Please see this page for help on customizing the unit conversions and constants.
Please see this page for help with common download and licensing issues.