Welcome to this installment of Math Teachers at Play! Three: It's a Magic Number!

Secondary Grades

Pat takes midpoint all the way through three dimensions for his precalculus class with Just an Average Point posted at Pat'sBlog.

Mr. D of I Want to Teach Forever shares a quality Bingo and a Matching Game for an Algebra 1 class in Two Review Games: Multiplying Polynomials and FOIL.

The Number Warrior, Jason Dyer ignores his lack of a handy lake, mountain, or orbiting satellite and has his students take measurements anyway in Imaginary Mountains (Laws of Sines and Cosines). He has lots of posts worth your time recently, check him out.

John D. Cook's When does the sum of three numbers equal their product? has a surprising result that I confess has me a little confused because I have to set down and hash out a proof for myself.

"Because acquiring this knowledge is difficult. Because you will feel triumphant when it no longer confuses you. Because you will enjoy what you can do with it. Because in learning it you may discover new perspectives on life, new ways of thinking. Because its possession will make you more alive than its alternative, which is ignorance."

- Banner & Cannon, The Elements of Teaching

Primary Grades

Denise explains how Math Facts Are Like Learning To Type posted at Let's play math!. Also click the link at the bottom of the story for the Game Worth 1000 Worksheets. I play these variations with my cousins every chance we get.

Cassandra Turner describes a nice mental math warmup in Number Strings as a Math Warm-Up.

William Wallace, when he's not leading Scottish revolts, re-invents that old standby binary trick in base three, with graphics.

Lists

Larry Ferlazzo provides a helpful list of lists: The Best Places To Find Theatrical Movies On Science, Math, & History.

Maria H. Andersen shares her Top 10 Technology Tools for Math - lots of good stuff here, and a few that were new to me.

In my search for distinctive features of various ages, someone (forget who, sorry!) turned me on to this cool list: What's Special About This Number?

Pi Day Roundup

Some math teachers were surely having some fun during this 2-week period, which of course contained the annual nerdvana, Pi Day. The value of this observance is in debate, as some celebrated enthusiastically and some remain dubious. This year congress made it official and Rachel Maddow let her geek flag fly. 360 told us about some things that equal pi and gave us a special edition pi day sudoku.

Unclassifiable

Here's a newfangled Rubik's Cube that will make your head explode.

Ian at Logic Nest reviewed JAME, fractal exploring software that looks amazing, and will hopefully be amazing once I actually have time to play with it.

Pagetutor uses Google Sketchup to give us some perspective on What A Trillion Dollars Looks Like. Like, in cash money. Stacked on pallets.

Jon analyzes Nim with some crazy directed graphs.

The TED site shows us Hans Rosling, using stats and infographs that will make you ooh and ahh, while oh by the way exploding myths about the developing world.

Have you done something fun lately that you want to share? Use the handy submission tool to get it in the next Math Teachers at Play.

And please indulge my favorite thing from the web in recent memory: