2.1 Due January 9

Once again, the reading was strictly review of material from Math 190 and I've done a lot with modular arithmetic outside of 190 anyway, so I feel very comfortable with concepts in today's reading. I didn't feel challenged at all, but I did come up with a question. The book showed that that addition and multiplication still work as normal in modular arithmetic, but I wonder if the same goes for exponential manipulation. I plan on exploring this question.

I was impressed on how the use of modular arithmetic could make some of the exercises of the last section much easier. For example, one of the exercises in 1.2 was to prove that a positive integer is divisible by 3 if and only if its digits add up to a multiple of three. This proof would have been much easier with modular arithmetic because it's clear that powers of 10 are congruent to 1 mod 3 and thus it's easy to show that the sum of the digits of any number is congruent to the number itself mod 3.