This is a simple product quantity selection form. The product value will be multiplied by the quantity amount, so the formula is:

`Price = Product * Quantity`

The quantity element overwrites the price in its position to act as the final price. If the option overwrite_price was set to “No”, the price would be added on top of the product price – we don’t want this type of calculation in this form.

The following image shows the options of the **Product** element which contains 3 products with individual values:

Now that we have our products set in the Product element, the next step is to add the calculation to the **Quantity** element. You can find the calculations in the Quantity element -> Calculation section:

The **red section** shows the calculation part (product value multiplied by the quantity numbers).

The **blue section** shows that the option overwrite_price is enabled so the price will be overwritten in this element.