If Friday the 13th is a bad luck day, does that imply that Monday the 13th is a good luck day? Compose a logical argument for this question. Whoever sends in the best logical argument, arguing either side of this question, wins a Singing Turtle reward. Read the post to find out the details.

# Archive | Philosophy

# eVersion of Algebra Survival Guide ARRIVES!

The award-winning Algebra Survival Guide is now available as an eBook. As such you can read it on any of these devices: Kindle, iPhone, iPad, Blackberry, Android, Mac or PC. Price of eVersion is just $9.95.

# How to Use Definitions in Geometry

Definitions are TWICE as useful as standard theorems in geometric proofs. This post explains why, showing that definitions are, in a certain sense, very much like “reversible coats.”

# Tutor Tales — Algebra/Arithmetic Connections

A cool way to help students learn from mistakes they make in algebra.

# Hopes for Obama and Education

In what direction will Obama take the United States in education? How will he handle the No Child Left Behind law? It’s anyone’s guess, so feel free to guess right here.

# Math + Questions = Life

Questions make math come alive. See an example that bursts open any sterotype that math is dull. See how math can be like a religious experience.