# M8.3.1

**algebraic expression**contains a variable which is a symbol representing an unknown quantity.

### Why Is There a Tidal Bulge Opposite the Moon?

Demonstrate and calculate the reasons for tidal bulges of water on both hemispheres of Earth, due to the Moon.

### What is Wind Chill?

Why is it that we feel colder when the wind is blowing than when the wind is calm? What does it mean when the local weatherman gives the daily high along with the wind chill? How is the wind chill determined?

### Just What is a Logarithm, Anyway?

Before we talk about logarithms, let's think a little bit about graphing.

### Algebra Magic - Create Your Own Number Puzzles

Many people think of algebra as dealing with solving equations that have letters and numbers, and that it is completely unrelated to anything outside the math classroom. Also, teachers have a difficult time motivating students to learn algebra. I have found that not only are number/magic puzzles quite common outside the classroom, but also that they motivate students, and that teachers can successfully use such number puzzles as an interesting lead-in to algebra. Here I discuss two number/magic puzzles that can be demystified and explained by using algebra.