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
Determines if the calculations in the current document should be kept up-to-date automatically:
▪Recalc automatically
| If this option is enabled, calculations are updated automatically when the content of a cell is changed. |
| This is the default setting. It guarantees that all calculations are up-to-date. |
▪Recalc only before ...
| If this option is enabled, calculations will be updated only when saving or printing the document, or when copying (or cutting) cells. If all of the above options are disabled, calculations will no longer be updated. |
| However, you can have the calculations updated manually at any time: To do this, choose the ribbon command Formula | group Update| Update data | Update calculations or press the F9 key. |
| See also Updating sheets. |
"External references" section
These options are related to external cell references (i.e. cell references that refer to cells in a different file). For more information, see External cell references.
Available options:
▪Update data on opening
| Lets you choose if 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. |
| 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, PlanMaker instead displays an error value when you update an external reference while the corresponding 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, in very rare cases, lead to very small rounding errors. This issue is not PlanMaker-specific but affects practically all computer applications.
However, PlanMaker has two options that, when enabled, almost eliminate such rounding problems:
▪If 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 reduces the probability of receiving a rounding error significantly; the second option reduces it even more. However, the disadvantage of enabling these options is that the time required to recalculate the document increases. |
| A classical example for such rounding errors: |
| If these options are disabled, the formula (0.1+0.2-0.3)=0 returns FALSE, though 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 values are taken over exactly as they are displayed to you after rounding to decimal places. The entered values are therefore truncated to the decimal places that are set in the cell options for the number format.
| An example for explanation: |
| You have the sum of 2.3 + 2.4. The exact result is 4.7. However, you decide not to display the decimal places after the decimal point. Therefore, you set the decimal places in the cell options to 0. The table shows 2 + 2 now. |
| Without enabling the option Precision as displayed: You get 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 get 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 Precision as displayed option: For longer decimal numbers than the decimal places that you have set for the number format in the cell options, the original, more accurate values are permanently lost. You should therefore be sure that you want to use this option in your calculation.
"Charts" section
Like calculations, charts are updated automatically when the content of any cell changes.
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 affects only cells containing a circular reference. For example, if cell A1 contains the formula =A1*2, this is called a circular reference, because the calculation in cell A1 refers to cell A1 itself.
If the Use iterations option is enabled, such calculations are repeated until a) the number of Maximum iterations is exceeded, or b) the difference between the current result and the previous result of the iteration is less than Maximum change.
By default, this option is not enabled.
Note: Unless you actually use circular references in calculations on purpose, this option should not be enabled, since it significantly increases the time required to recalculate the document.