How to rate the answers with the value and then get tha total value for all questions

Welcome to the ODK forum, @Symon! We're glad you're here. When you get a chance, please introduce yourself on this forum thread. I'd also encourage you to add a picture as your avatar because it helps build community!

You can do this by using 1 and 0 as the name value of the "yes" and "no" answer options, and then using a calculate type question to add the answers to all your questions together. Note that it cannot add correctly if there are unanswered questions - it will show "NaN" or "not a number" until all questions are answered.