On the Calculate tab in the dialog box of the ribbon command File | Properties 
, you can change settings for the calculations in the current document:
"Recalculation" section
Here, you can determine whether the calculations in the current worksheet should be updated automatically when you make changes to the worksheet contents:
▪Recalc automatically
| If this option is enabled, all calculations are updated automatically when the content of a cell is changed. |
| This is the default setting. It ensures that all calculations always provide up-to-date results. |
▪Recalc only before ...
| If this option is enabled, calculations will be automatically updated only when saving or printing the document, or when copying (or cutting) cells. If all three options are disabled, calculations will no longer be updated automatically. |
| However, you can have the calculations updated manually at any time: To do so, choose the ribbon command Formula | group Update| Recalculate or press the F9 key. |
| For more information, see also Updating sheets. |
"External references" section
Here, you can make settings for external cell references. These are references that refer to cells in other workbooks. For more information, see External cell references.
Available options:
▪Update data on opening
| Here, you can specify whether all external cell references in a document should be updated (once) when the document is opened: |
| Always: When the document is opened, update its external references automatically. |
| Never: When the document is opened, do not update its external references. |
| Ask user: When the document is opened, ask the user if external references should be updated. |
▪Save external data in document
| If this option is enabled, PlanMaker saves a copy of all values returned by external cell references in the document. If the file for an external reference is missing when the external reference is updated, the value last stored will still be displayed. |
| If you disable this option, an error value will be displayed instead if you update an external reference and the associated file cannot be accessed. |
"Rounding" section
Enabling these options increases the accuracy of calculations. Since computers use a different numeral system than humans, some calculations may lead to very small rounding errors in very rare cases. This issue is not PlanMaker-specific but affects practically all computer applications.
However, PlanMaker has two options for eliminating these rounding errors as much as possible:
▪If the option Round final result is enabled, PlanMaker automatically rounds the final result of each calculation to 15 decimal places.
▪If Round intermediate results is enabled, PlanMaker also rounds any intermediate result within a calculation to 15 places.
| The first option already significantly reduces the probability of obtaining a rounding error, while the second option makes this even less likely. The disadvantage of both options, however, is that the recalculation of worksheets takes a little longer. |
| A classic example of this rounding problem: |
| If both options are disabled, the formula (0.1+0.2-0.3)=0 returns FALSE, although TRUE would be the correct result. If both options are enabled, the calculation returns the correct result. |
▪A third option is Precision as displayed: If you enable this option, all numbers are applied exactly as they are displayed after rounding to decimal places. This means that the values that are entered are truncated to the decimal places set in the cell options for the number format.
| An example for illustrative purposes: |
| You have the sum of 2.3 + 2.4. The exact result is 4.7. However, you choose not to display the decimal places after the decimal point. You thus set the decimal places in the cell options to 0. The table now shows 2 + 2. |
| Without enabling the option Precision as displayed: You obtain the result 5 (because the values 2.3 + 2.4 still exist in the background and are rounded to 5). You can also continue to calculate with the exact result 4.7. |
| By enabling the option Precision as displayed: You obtain the result 4 (because only the values 2 + 2 exist, exactly as they are displayed in the cell). However, the exact result 4.7 has been lost for further calculation. |
Note on the option Precision as displayed: If decimal numbers are longer than the decimal places that you set for the number format in the cell options, the original, more accurate values are permanently lost. You should thus be sure that you want to use this option in your calculation.
"Charts" section
Like calculations, charts are automatically updated by default when the content of any cell is changed.
If you don't want this, disable the option Update automatically in the Charts section.
Charts must then be updated manually if necessary. To do so, choose the ribbon command Formula | group Update | Update data | Update charts.
"Iterations" section
This option only affects cells that contain a circular reference. If, for example, cell A1 contains the formula =A1+A2, this is called a circular reference because the calculation in cell A1 refers to cell A1 itself.
If the option Use iterations is enabled, such calculations are repeated each time the worksheet is recalculated until either the number of Maximum iterations is reached or the result of the calculation differs from the previous result by less than the Maximum change.
Normally, tables should not contain circular references, thus this option is disabled by default.
Note: Unless you actually use circular references in calculations on purpose (for example, to determine values using an iteration method), this option should not be enabled, since it significantly increases the time required to recalculate the worksheet.