What is JotForm?
JotForm is a free online form builder which helps you create online forms without writing a single line of code. No sign-up required.
At JotForm, we want to make sure that you’re getting the online form builder help that you need. Our friendly customer support team is available 24/7.
We believe that if one user has a question, there could be more users who may have the same question. This is why many of our support forum threads are public and available to be searched and viewed. If you’d like help immediately, feel free to search for a similar question, or submit your question or concern.
The updates in the Calculation wiget allows you to build your formulas with no need to type any digit on it, all you need to do is to click on the needed buttons. Please see this gif screenshot:
I hope this helps. Please inform us if you need further assistance with this inquiry.
Here is also a guide that will explain you with more details how to use it: How to perform calculation in the form