In particular CS at MIT ~was~is in the EECS department. MIT also begins with calculus (18.01), not algebra or pre-calculus or anything else. Newton's method, at least in my undergrad (Georgia Tech, not MIT), did introduce Newton's method at some point (I cannot remember the context, but I do remember it in my first or second calculus course). Since SICP students would have taken or be taking Calculus at the same time, it wouldn't be a stretch for them to have seen those sorts of problems already.

cs at mit is in the eecs department.

Oops, yeah. That wasn't supposed to be past tense.

haha. no worries. :)

I posted the link elsewhere but if you take a look at this talk https://www.youtube.com/watch?v=O3tVctB_VSU it will give you an idea of where Sussman is coming from.

Also, I think right in the beginning of the very first lecture of the series Abelson talks about Computing as a way of codifying processes. In the link I included, Sussman says flat out that what he's interested in is using Computing as a better way to teach physics.