6.1 (second half), due February 23

I've having a fairly hard time thinking about mod I where I is a subring because (like the book said) it's arbitrary and I can't think about it with any specificity. The whole coset thing seemed to just suddenly appear so that was also confusing. It's cool that we have this new way of looking at congruence and new ways of defining these things but I just don't understand it very well yet.