# Find the Sum of a Repeated Variable

When Number variables are used in repeated dialogs, you can use the SUM expression to add repeated number values. For example, if a repeated dialog is used to gather information about an individual's credit card balances, a computation can add the balances together to find the total amount owed.

In addition, you can use the SUM expression in a computation script to add computation values that have been repeated.

In the following example, let's say you have a repeated dialog that contains three variablesâ€” Item, Item Amount, and Item Quantity. For each line item, you create a fourth variable, a computation called Total Amount that multiplies Item Amount by the number of items the user purchases (or Item Quantity). You can then add all of the Total Amount values and receive one sum total.

## Example

```//Example 1: Sum of a repeated Number variable.
SUM( Num Var )

//Example 2: Sum of a repeated Computation variable.
SUM( Total Amount )```

 Num Var A Number variable in a repeated dialog. Item Amount A Number variable in a repeated dialog. Item Quantity A Number variable in a repeated dialog. Total Amount A Computation variable that multiplies two repeated variables in its script (for example, Item Amount * Item Quantity).