Sorry a real newb here with no code experience but would appreciate some help with this plugin.

There are 3 fields (<%fieldname1%> <%fieldname2%> <%fieldname3%>) for a user to input numbers, these numbers are multiplied together then the user will choose an option from a drop down list.

Option A (poor insulation) will divide the total by 10

Option B (average insulation) will divide the total by 15

Option C ( well insulated) will divide the total by 25

So far in the calculated field i have

`(fieldname1)*(fieldname2)*(fieldname3)`

This gives me the total for the first 3 fields and to divide that number i put this

`(fieldname1)*(fieldname2)*(fieldname3)/10`

But how do i divide the total by the option the user selects?