Theory of Numbers
An introduction to number theory from MIT OpenCourseWare, requiring no abstract algebra background. The course covers primes and their distribution, congruences, quadratic reciprocity, diophantine equations, irrational numbers, continued fractions, and partitions, building from elementary techniques toward the classical results that underpin modern cryptography and algebra. Materials include lecture notes, problem sets with solutions, and exam materials drawn from MIT's actual undergraduate offering. The course is self-contained enough for independent study, working through proofs of results like the infinitude of primes and the law of quadratic reciprocity in detail. As with other MIT OpenCourseWare offerings, all materials are free to use under a Creative Commons license, with no enrollment, instructor access, or certificate attached.