Some ideas just slap you in the face. I got slapped this morning as I was flying home from LA to Albuquerque. Those little cocktail napkins they hand out with “beverage service” often give me the urge to write. So this morning, nerdily enough, as I sipped my orange juice at 30,000 feet above the [...]

# Tag Archives: Algebra

# Origins of the Coordinate Plane

One of the legends of math relates to the invention of the coordinate plane system. The legend states that Descartes was inspired to invent this system after watching a fly move around on the ceiling over his bed. This post tells the story and points out its relevance for modern math teachers.

# Not all variables are created equal

Variables do not all serve the same purpose. Making this clear helps students more deeply understand algebraic equations, such as the equation for a line. This post shows how to understand the two kinds of variables in the slope-intercept form of a linear equation.

# Common Algebra Mistake: Interpreting Negative Signs in Front of Parentheses

Tricky area of algebra: negative signs in front of parentheses. This explains how we can help students relate the concept to everyday life, and thereby grasp it so they remember it!

# How to Survive College Algebra

You can survive College Algebra if you have the right tools. One of the best tools is my Algebra Survival Guide, which has helped more than 100,000 people succeed at this difficult subject. The Algebra Survival Workbook helps by providing additional practice problems. Check them out at Amazon.com

# Tutor Tales — Algebra/Arithmetic Connections

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

# Challenge Problem – the ANSWER

Answer to challenge problems about probability of catching fish.

# Conquering Mixture Problems — Answers

Answers to three mixture problems.

# Conquering Mixture Problems — Practice

Solve these mixture problems to increase your skill at solving tricky algebra word problems.

# Conquering “Mixture” Problems, Part 1

Mixture problems … they may look impossible. But when you use “master equations,” it turns out that they are easy to solve. This little post shows you how to get started taming these problems.