## Adding a formula to a repeated section

Let’s focus on how you can repeat formulas. For this, you will have to go back to the main branch of the decision tree.

One of the pieces of information asked in this decision tree is the monthly salary of the employee. With formulas, we can easily add up all of these individual salaries. Before we have asked any salary, our total should be zero (0). Then, after each time we acquire an individual salary, we will add this to the total.

In the Berkeley Studio, we will first add a formula called `totalsalary`

to hold the total salary and to which we will add up all salaries of our employees. We will initialize it to zero (0):

Now we have the formula called `totalsalary`

, copy and paste this formula to the same Actions panel, so that we have two identical formulas. Now we will edit the second formula in the Actions window so that it will accumulate all salaries into the total salary.

Open our second `totalsalary`

formula. In the text box called Formula, we’ll add the salary of each individual employee to this total. In order to do this, we type the following:

```
totalsalary + gperson[counter].salary.salary
```

As in the picture below:

### The correct order of the Actions list

Now, make sure the initial formula (setting it to zero) comes **before** the repeated section indicated by the `repeat`

item. And move the second formula so that it is **within** the repeated section, but **after** the graph call in which we ask our employees’ details, so between the `call graph`

item and the `until`

end condition.

### Showing the total salary

Now let’s show this total salary to the end-user: Make a separate ending node, titled `summary`

. In this node, add a text that refers using caron syntax to the `totalsalary`

formula in the node `employees`

:

```
Total salary: ^{employees.totalsalary}
```

Now if you run the model and add a few random salaries, you should see that they will be added up correctly and shown afterwards.