You can use the SUM function to add the two scores and then divide by 2 to calculate the average. SUM( question#1, question#2) / 2 where question#1, question#2 are questions you want to add. You must type @ and select the required field from the list to include them in the formula above.

Thanks! I have one more question. Would it be possible to create a conditional message based on two totals to sees in the end of the form after sent?

Currently you can show a conditional message based on one of the scores only. For details, refer to the help article below. https://formfacade.com/calculate/add-verbal-assessment-conditional-message-based-on-calculated-score-google-forms.html