# Your first Formula

Formulas in iDoceo will let you calculate a column of results using any combination of:

• Columns from any tab in your grade book
• Arithmetic operations
• Functions
• Conditions
• Constants

Here is how we add a formula in our gradebook class Formulas: Add Calculation > Formula

It is a very powerful system with unlimited possibilites and combinations

Formulas do not take into account the grade type property of a column since they offer a wider range of options and functions.

We will add a formula to our gradebook, a simple average, just like that:

Here is the calculation result of our sample data

And this is the formula setup, a simple average between test1,test2 and test3

A formula accepts columns also from other classes.

#### Working with functions. Skipping empty cells

When calculating averages, it is often required to skip empty cells (i.e. absent students) so that the average only takes into account those cells that actually hold a value
Our previous formula would consider an empty cell as 0 and the average's result would not be correct.

iDoceo's formulas will let you choose from a wide variety of Functions.
In short, a function works like this: you configure its input values - called arguments or variables - and it will yield a single result (its output)

You will find a short description under the Functions button and you will see how to work with it.

The function we need in our case is called Flexible average

The description of this FLEXAVERAGE function explains that it requires a variable number of arguments, hence the ellipsis and that it will automatically skip empty cells

This is how our previous formula would look with this function

And this will be the formula in action. We have added a few empty cells this time

#### Related articles

Rounding a Formula's result
Formulas: How to use its functions
Formulas: IF condition