Well, the 2 extra lines come from the 28s being a graphing calculator, they're essentially free. They're nice, but having gone from 1 line in an 67 to 4 in the

Well, the 2 extra lines come from the 28s being a graphing calculator, they're essentially free. They're nice, but having gone from 1 line in an 67 to 4 in the 28s, I'm pretty sure the important threshold is "more than 1 line". On the other hand, I wouldn't want to switch to a 35s because I read it has a stack of only 4 levels. I find it very useful for summing a long list of numbers to key them all in, and then double check against the list as I do each addition. Hmmm, it's also easier to keep track of where you are in that process with an extra 2 visible lines.