Yes, you can suggest to switch to slides, but it is unlikely to get the result you wish (it is a relatively crass change; and if the prof thought it would be a good idea to do that, he would already be doing it).
A better approach is usually to change yourself:
When you sit in a lecture with a chalkboard, it is a good opportunity for you to be extra attentive to what the lecturer is saying or writing on the board. The temptation may be there to just make a verbatim copy of whatever is written on the board as quickly as you can, but back in my time as a CS/maths student that was not my preferred way to do it - those sessions were usually half wasted on me, as I was so consumed by the copying process that I didn't get to really think along with the lecture.
Instead, try first and foremost to understand what the prof is trying to communicate (through words and the chalkboard). Assume that the salient points make sense, even if the presentation has errors, and then be gentle about asking questions. I mean, obviously, unless the prof makes it clear that they don't want questions - and always in a polite manner. Also, if you raise your hand, make obvious eye contact etc. and he ignores you, then so be it. Avoid interrupting verbally unless the prof is of the type that always faces the board instead of the room.
If it is just an obvious typo, then you can gloss over it and fix it yourself in your copy (maybe make a side note to check up on this). If it is a glaring error (which the prof should really have noticed), then ask if this is intentional - if it is, then this point may be something you misunderstood, and by asking, you give the prof a chance to clarify.
Finally, if you get the sense that you have no idea what's going on at all, feel free to ask your prof in the break or after the lecture; or figure out if the prof has an open hour for students.
In any case, it is always a good idea to know which textbook or other material works well with the lectures, and have it handy, to look up mysterious passages at home. The point of lectures at Uni is to act like a guideline - if the topic is relatively easy you can get away with no further studies, but thinking and working on these things afterwards should be a normal part of your process. Be glad if a prof gives great handouts, but by all means do not expect this to be the case.
This holds doubly so if you cannot get a handle on the topic during the lecture at all, and are totally confused. Don't try to somehow fix the lecture; instead try to at least get the big picture, and then work on it afterwards.