I believe that the number after the / would be your line height. So for the h1, 1.75em would be your font size and the 1.1429 would be your line height. His comment is probably just what those values equal in pixels since they are easier to keep track of then ems (at least in my opinion).
Thank you so much!!! Now I understand. I was always wondering about the relationship between the font size and the line height. What are the criteria to determine what line height would be suitable for a certain font-size?