Excel has a feature that, at default, is set to automatically recalculate formulas and functions any time a change is done to the page. This feature can be turned off in the options menu and should be turned off when using the random functions that will be outlined in the next few slides. Once this feature is turned off, the formulas and functions can be recalculated by pressing F9.

So, to turn this re-calculation feature off, go to:

Tools > Options > Calculation (one of the tabs)

Once here:

• select manual calculation
• then save by clicking on OK, as demonstrated below.