And it is with pride that I welcome you all to my first issue, and the third issue all in all, of the Carnival of Mathematics. I probably should apologize as well - my announcement stated March 8th, but that was before I really looked at the dates involved, so we did, alas, miss the international women's day. We haven't had quite the rush that Mark CC enjoyed, but we'll make a good one even so.

First out, from the first half of our submissions, we have a grand tour of didactic topics, starting out with Michael Tang, who shows us why negative times negative is positive, with a touch of ring theory into the mix. Following that, Rebecca Newburn discusses equation solving strategies and Laurie Bluedorn takes a historical view on the age of introduction of formal arithmetic. To finish it up, jd2718 tells us about teaching complex numbers and your humble host has a manifesto of sorts about stimulating strong students.

From the financial mathematics half of our submission, Matthew Paulson analyzes payday loans.

For the third half of the submissions, we look at humor. Scott Cram gives us mathematical humor cavalcade, funky tricks with π and more funky tricks with π, including how to calculate it with frozen hotdogs. Denise brings us a corollary to the well-known theorem that all odd numbers are prime.

The fourth half of our submissions climb the dimensions ladder. Eric Kidd brings us a review of a newly released e-book in linear algebra, and Lynet discusses visualization and abstraction of higher dimensional entities.

The fifth half concerns itself with number theory, geometry, topology and algebra. We start out with Mark Dominus who discusses integer partitions and odd correspondences. Charles Daney chimes in with diophantine equations - and we use it immediately, as Foxy takes us along, finding square sums of squares in magic squares. For the geometric side, polymath has a proof of Morley's theorem, and trust me: you do want to read the proof before you look up the theorem. Alon Levy raises the level another notch in a discussion of infinite galois theory - a part of his ongoing series on galois theory. Mark Chu-Carroll steers us over to the topology side with a discussion of homotopy - one of my own favourite subjects - and follows up with an introduction to simplicial complexes: an invaluable tool for algebraic topology. Which brings me to the last post - also from your humble host. an introduction to algebraic topology.

The next Carnival of Mathematics will be hosted by Jason Rosenhouse and the Evolution Blog. Submissions go through Alon Levy at alon_levy1 (at) yahoo.com, through the submission tool or could even be forwarded by me - reachable at mikael (at) johanssons.org