The instructions on the first sheet tell you how to determine the number of turns: 360 / (degrees per turn x number of desired spacings). Enter the number of turns in cell A4. Enter a tolerance in cell K4 - you can pick an arbitrary number like ".01" to start with. The spacing will be calculated and results will appear in the table. Take a look at the following:
If we want 127 spaces then the starting number of turns is 360 / (5 x 127) = .5669 since the integer of this fractional number is zero, then "0" should be entered in cell A4. After entering an allowable error of .01 in cell K4, the various combinations of hole plates and space number are shown. Four different combinations are shown: 127.385 for a hole plate of 23 and 13 spaces is one example. The best combination is hole plate 30 with hole spacing of 17.
So for this particular example, there are no WHOLE turns for each spacing, the dividing head is rotated just enough so that every 17th hole on the 30 hole plate provides one of the 127 spacings. To check this: 360 / (17/30 x 5) = 127.059
I'm sorry that this sounds cryptic but like most software, it is completely clear to the programmer. I'd not intended this spread sheet to be used by others so it is not well documented. I wrote this years ago and have never posted it on any forum for the reason that I do not have the time to explain how to use it to every person that is interested.
The best way to learn how to use the spread sheet is the same process as we often learn how to use machine tools: by using it. Experiment by entering some variables that correspond to known solutions. If necessary, after customizing the sheet to conform to your own dividing head, use the spread sheet to determine some solutions and then try them out on your dividing head.