How can I allow users to add "other" fields?

I have a checklist of items created using multiple choice element. Is there a way to add more then one "other" field that the user can edit? If not is there another type of fields that users can edit that is able to be used in calculations? 

I think the User contributed checkbox widget should work for you. 

http://widgets.jotform.com/widget/user_contributed_checkbox

Unfortunately, the calculation values cannot be set as in the native checkbox field. However, you may setup conditions to perform calculations on the form based on the values entered something like below.

Let us know if that helps.

This worked perfect thanks so much!