Sections 2.1 and 2.2, due on August 31

The most difficult part was the idea of ordering and the induction principle. I did not quite grasp what the induction principle actually means. Is it say that all subsets of N can be mapped to N? Basically, how to use this principle in conducting a proof.

The discussion of the GCD and LCM, and especially how their product is ab startled me. I had never really thought if it that way before. Furthermore, while I have heard of the GCD being the least element of the set of linear combinations, it is still not intuitive to think of it in that manner.