Chapter 11 of 24 - Rings and Polynomials

New mathematical objects! Introduction to rings. Introduction to fields. Introduction to polynomial rings over fields. An interesting return to long division (!) with polynomial division, and some great examples of shortcuts for factorising polynomials and finding roots. Can't help but feel we should have been taught about these shortcuts earlier. Not only do they seem really valuable, they're also surprisingly interesting and can probably be taught without rings and fields as a prerequisite.