# None values

Cells without a formula, or formulas that lead to calculations such as a division by zero, evaluate to the

`none`

value. This is a special value in Causal, and can also be derived by using the `none`

helper variable, or by adjusting the Empty Value setting of a variable to `none`

.`None`

is special in that any mathematical operation it is part of also evaluates to `none`

- for example, 1 + `none`

= `none`

.The exception to this is in aggregations: when aggregating a category's items,`none`

values are simply excluded from the computation. This is because it is useful to see aggregated values even if some underlying cells contain`none`

values, as is typical in use-cases such as headcount modelling.For example, if you're wanting to see the average bonus across your employees, but exclude from the average those employees who do not receive a bonus (and therefore are`none`

), you would do the following to the Bonus by Employee variable:

Set empty value setting to`none`

🚨 Note that if you try to use that aggregated variable in another formula - it will be treated as`none`

- see Troubleshooting for more.

Last modified 10mo ago