2.2 Setting the Workbook to Manual Calculation

The random number generators of Excel have the characteristic that whenever a command is entered anywhere in the active workbook, the random numbers change because they are recalculated. To prevent this from happening, change the recalculate mode from automatic to manual.

2.2.1 Manual Calculation on a PC

1. Select File then Options.
2. Click on the tab labeled Formulas.
3. Select Manual Calculation for Workbook Calculation and uncheck the option Recalculate workbook before saving.
4. Then press OK.

Figure 2.4: Calculation options under Formulas in a PC.

2.2.2 Manual Calculation on a MAC

1. Go to Excel Menu then select Preferences

Figure 2.5: Preferences in the Excel Menu on a MAC.

2. Under Formulas and Lists, click on Calculation

Figure 2.6: Formulas and Lists in Preferences on a MAC.

3. For Workbook Calculation, select Manual calculation and uncheck the option Recalculate workbook before saving.

Figure 2.7: Calculation Options on a MAC.