Form Calculator to achieve conditional logic

Can i achieve logic like this, if a field is 10, i will update another field to be 1. Basically what i want to achieve is to free customer 1 item for every 10 items they purchase. Buy every 10 item free 1 item.

Free item = ( x Modulus 10), where X is number of item customer purchased.

10 MOD 10 = 1

15 MOD 10 = 1

20 MOD 10 = 2

You can use the Update/Calculate condition to show the Free item quantity based on the total quantity value.

Here is a sample condition:

Similarly, you can create conditions for values greater than 20, 30, etc. Here is how the form will look:

Hope this satisfies your requirement. If not, let us know and we'll be happy to provide any further assistance.