Well, as I just happen to have a Rolleiflex sitting on my desk:
The top line, going from left to right: 1,2,3,4,5,6,7,8. Below that, and lining up under these numbers:
f:22: 250 125 60 30 15 8 4 2
f:16: 125 60 30 15 8 4 2 1
f:11: 60 30 15 8 4 2 1
f: 8: 30 15 8 4 2 1
f:5.6: 15 8 4 2 1
f: 4: 8 4 2 1
f:3.5: 6 3 1.5
f:2.8: 4 2 1
I don't know that much about Rolleis, which sounds silly as I've been using them for years, but those weird numbers at f:3.5 may indicate that you can get them by setting the f: stop indicator between say, 3.5 and 2.8; and between 2 and 1?
In all the years I've used them, I confess I never really looked at the chart until this moment, as I've always used either a meter, or an educated eye.
By the latter term I mean this: When I first started out I dogged the footsteps of a freelance photographer, Roy Shigley. He used a beat up, meterless Nikon, or maybe it was a Pentax, I don't remember for sure, but he sold a lot of photographs. He would look at a scene and say, "f:8, 1/125th." I would consult my meter. Same thing. After a time he said, "Leave the meter home." Then it would be my turn: "f:11, 1/250th." (brighter scene). I'd be right, or I'd be wrong, but with practice, lots of practice, eventually I too (feeling very professional by now), would appraise a scene and say, "f:8, 1/125th." Shigley would look at me and wink.
So the earlier advice from Peter about starting out with a meter and learning to appraise with your eye as the meter does, will finally work if you're patient. Well, most of the time. There will be those tricky situations that will fool you. Sometimes they'll fool the meter, too. Which is where bracketing comes to the fore. Bracketing is the cheapest insurance I know of.
Ted