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Calc FAQ

Solutions to Common Problems running Calc

Q: Can I get rid of the Flow Simulation splash screen when Calc starts?

A: Please do not attempt to remove the Flow Simulation splash screen. Calc is not idle while the splash screen is displayed, but is actually loading the physical properties and constants, so there would still be a delay even if the splash screen were removed.

Q: Why can't I use the computer keyboard instead of clicking with the mouse on the buttons?

A: Use the keyboard shortcuts. The keyboard shortcut keys are listed in the documentation ordered by key and function.

Q: Could you please provide a list of the keyboard shortcuts?

A: The keyboard shortcut keys are listed in the documentation ordered by key and function.

Q: How do I make the button legends bigger?

A: Click on the "opt" button or Options menu to bring up the Mode dialog box. Select the "View" tab and click on either the "Main Keys" or "Function Keys" buttons to change the button size, spacing, font etc. For more information, see the documentation.

Q: How do I make the display bigger?

A: Click on the "opt" button or Options menu to bring up the Options dialog box. Select the "Display" tab to change the font, size, background colour etc. For more information, see the documentation.

Q: Where are Calc's statistics functions?

A: Click on the "opt" button or Options menu and select statistics mode. See the online documentation.

Q: Where are Calc's financial functions?

A: Click on the "opt" button or Options menu and select financial mode. See the online documentation.

Q: Where is the pi button?

A: Use the shift button to get additional functions in normal operation. See the online documentation.

Q: Where is the percent button?

A: Use the shift button to get additional functions in normal operation. See the online documentation.

Q: How do you get mode selections to be the default mode?

A: Calc saves its settings in the Windows Registry automatically when it exits.

Q: How do you get the button size to stay at a given size?

A: Calc saves its settings in the Windows Registry automatically when it exits.

Q: How do I view the stack in RPN mode?

A: For version 5.3, click on the "shift" button, and then the "stack" button, or use the keyboard shortcut (Ctrl-^). For version 5.6 and later you need to enable the stack in the Options/Display dialog.

Q: Where is the button to exchange X and Y in RPN mode?

A: For versions up to 5.3, you need to click on the "shift" button, and then the "x><y" button. On these versions to get the number into the X register you need to do an "Enter" (this is not quite the same as on HP calculators). So the sequence is:
2 Enter 3 Enter X><Y divide, result 1.5 (not 0.6666667).

Q: Why, after using for a while in RPN mode, do I get a stack full message?

A: In RPN it is possible to keep pushing values onto the stack which for one reason or another never get popped off again. Although the stack is quite deep (16 levels) it will tend to fill up over time if this keeps happening and the calculator is not cleared periodically. This results in the error message when you try to push more values onto the stack. Hewlett Packard calculators simply discard values off the end of the stack when this happens, and some people expect this behaviour. Versions from 5.6 onwards behave more like the HP calculators. In the meantime it is suggested that the stack is periodically cleared, e.g. when starting a new calculation, to avoid the stack gradually filling up over time. This problem does not affect versions 5.6 onward.

Q: Where is the button to move the stack down in RPN mode?

A: On version 5.3 you need to click on the "shift" button, and then the "R<" (stack roll down) button.

Q: Why do the trigonometric functions give inaccurate values (e.g. sine of 10 degrees gives -0.5440211109)?

A: You have the angle mode set to Radians, instead of degrees. Click on the "opt" button and select the "Mode" tab or use the Options/General menu, and select "deg" as the angle mode. The correct answer for the sine of 10 degrees is 0.1736481777 .

Q: Why do the trigonometric functions give inaccurate values (e.g. sine of 10 degrees gives 0.156434465)?

A: You have the angle mode set to Gradients, instead of degrees. Click on the "opt" button and select the "Mode" tab or use the Options/General menu, and select "deg" as the angle mode. The correct answer for the sine of 10 degrees is 0.1736481777.

Q: How do I clear the Memory?

A: To clear the memory, clear the calculator using the "AC" button (or just clear the display using the "C" button), then click on "Min"

Q: Is there a way to get Calc to put the decimal point in automatically (like an adding machine)?

A: No. Whilst this can work well for an adding machine as used for book-keeping, it would be very confusing for a general purpose calculator. A simple solution is to simply work in pence, rather than dollars or pounds. The danger with this is that you forget to enter the zeroes for the pennies when entering a round number of pounds or dollars, especially if you do not use calculators exclusively in this way.

Q: How do you change the decimal point symbol?

A: Click on the "opt" button or Options menu and select the "Display" tab/submenu. You can then change the decimal symbol. When you install for the first time it should default to the regional setting on your computer.

Q: How do you change the thousands separator?

A: Click on the "opt" button or Options menu and select the "Display" tab/submenu. You can then change the digit group symbol, or disable it (by setting to "no").

Q: Why, if I enter "1 + 2 x 3 =" do I get 7 and not 9?

A: The order in which arithmetic operations is carried out is called precedence. Calc defaults to algebraic precedence which is the way most scientific calculators work. This means that multiplication takes precedence over addition, which is equivalent to 1 + (2x3) = 7 because the multiplication is evaluated first, even though it was the second arithmetic operation entered . Some calculators (particularly very simple ones) do not use algebraic precedence and only the order of entry is significant, so (1 + 2) x 3 = 9. Calc can be configured to use either type of precedence by clicking the Mode button and selecting the Mode tab. There is a section on this tab page called "Precedence" which gives you three options: As Entered, Algebraic (the default) and a third option "RPN" (Reverse Polish Notation; a very elegant solution which allows you to enter complex expressions without using parentheses, and made popular by Hewlett Packard's calculators). If you switch to "As Entered" mode, the calculator will compute "1 + 2 x 3" as 9.

Q: Why is the value truncated to two significant figures when I try to calculate a monthly interest rate?

A: When you switch to financial mode, the display automatically switches to Finance mode (i.e. two decimal places). This means that if you calculate a monthly interest rate (which is likely to be some fraction of one percent) there is not sufficient accuracy unless you flip back to decimal mode. To change to monthly interest rate, use the buttons on the rates dialog which converts without losing accuracy. From version 5.6 onwards the rate for monthly interest and other periods is computed automatically when the appropriate settings are made in the Rate dialog box.

Q: Why does Calc minimize after a period of inactivity?

A: This is usually because the "auto power off" feature is enabled. See the online documentation.

Q: Why do I get a message "Unable to open properties database" when I start Calc?

A: For some reason Calc could not load the properties and constants data. These are stored in files in your installation directory with the extension .PRP. Calc looks for a file called DEFAULT.PRP in this directory, which is where you would store customized properties and constants data for automatic loading. If this file is not found, the file FACTORY.PRP is loaded from the same directory. If both files are missing or inaccessible for some reason, Calc fails to load the data and the properties and constants will not be available. Check if these files have been deleted or moved. If no properties files can be found, they can be replaced from your backup copies of the distribution files, or you can re-run the Calc setup.

Q: Why do the HEX input keyboard shortcuts A-F only work with the keyboard shift?

A: Some of the lower case letters a-f are already used for other functions.

Q: Why do I get incorrect results after performing division in HEX mode (or other integer mode)?

A: If you perform a division in HEX or other integer mode the fractional part of the calculation is retained, although it is not visible. If you switch back to Decimal mode you can see the full precision of the result of the division. The hidden fractional digits sometimes account for an unexpected result on a subsequent multiplication, for example. Versions 5.6 and later of Calc have an "Int" function which can be used to truncate the fractional part. With earlier versions of Calc you can achieve the same effect by the "trick" of using Copy then Paste to re-enter the value as a string which has the effect of removing the fractional part.

Q: Why do am I getting the message "No Data" in the display?

A: Sometimes this happens if the data file has somehow become corrupted. Delete the file "default.dat" which should be in the Calc98 directory. On Windows CE devices it may be in the "My Documents" folder.

Q: How do you input times in hr/min/sec?

A: Use the sexagesimal input button as follows:

After entering the number of hours (if any) click on the "hr" button. The "hr" button legens changes to "min". Enter the number of minutes, and click the "min" button, which now changes to "sec". Enter the number of seconds. From version 5.6 onwards use the ":" button for each input.

Example (version 5.3): to enter a value of 2 hr 55 min 40 sec

  select Time mode.   clear calculator.  enter 2  click "hr" (2nd button, 3rd row on function keypad - changes to "min").  enter 55, then "min" ("hr" button legend has changed).  enter 40, then "sec"  click "=" : result 02:55:40.00  

To use the keyboard, enter the number of hours, then use the "h" key instead of the "hr" button. Enter the number of minutes. Now it gets a bit less intuitive, because the "hr" button on the keypad on the screen changes to "min", but you still use the "h" key. Now enter the seconds, if any, followed by "h" again, then the enter key for equals.

The sequence is: "2h55h40h(return)". Any leading zeroes and the final "h" can be omitted.

For version 5.6 use the ":" button or key instead of hr/min/sec or the "h" key.

Q: Why am I getting odd fractions denominators in feet/in mode?

A: Check that you have not set the maximum denominator to a value less than 64 in the Options/Display dialog. Values lower than 64 will take precedence over the default value of 64 for this mode.

Q: Why don't the depreciation functions work as shown in the manual?

A: There is a bug in some versions of the documentation (version 5.6) - you need to perform the depreciation function first, then multiply by the capital cost less any residual value. E.g.: 10 SLD 5 = X (10000 - 1000) = This only applies to algebraic mode - the RPN example is correct.