A: Calculator provides these 4 operators - Add, Subtract, Divide and Multiply and Scores are carried from one question to the next. Currently it provides Total score only​. Custom variables/Category wise scores, which will allow formulas will be available around next week.

https://help.getformly.com/en/articles/9294134-add-scores-and-calculations-to-your-forms

​You can show different Thank you screens based on total scores, options selected etc.
https://help.getformly.com/en/articles/9317047-create-a-quiz

Also, you can send conditional email notifications based on score.
https://help.getformly.com/en/articles/9236720-email-notifications