ôô

# What Are Variables? Part 1

How do variables work? How do you work with variables? And what’s up with x? Math Dude has the scoop on variables, algebra, and more.

By
Jason Marshall, PhD,
April 11, 2013
Episode #149

Page 1 of 3

Now that we’ve tackled the big question, What Is Algebra?, we’re ready to start talking about algebra’s finer points. Last time we learned that algebra is really just arithmetic…with variables, which means that variables are going to play a key role in our story. So over the next few weeks we’re going to take a closer look at exactly what variables are, what you can do with them, how to name them, and we’ll also talk about why that little letter x has become so famous.

Sponsor: This podcast is brought to you by Betterment.com. Betterment offers users an easy way to invest. No prior investing experience is required. Users choose how to allocate their money between two pre-set baskets—a stock basket and a bond basket. Signing up takes less than 5 minutes, and money can be added or withdrawn at any time without a fee. Users who sign up at betterment.com/mathdude will receive a \$25 account bonus as long as their initial deposit is \$250 or more.

## How to Name Variables

The first thing we need to do is pick a character for our story. In other words, we need to choose a symbol for the variable we’re going to talk about. As you may know, the letter x is used all the time in algebra and, of course, it’d work just fine for us here, too. But just for fun we’re going to be adventurous and instead use a symbol that looks like a box as our variable of choice for the next few weeks.

Why a box? Is this symbol special in some way? Not at all! The truth is that we could have picked absolutely any symbol we could think of—or even one that we couldn’t think of (if we could only think of it). Why do we have such tremendous freedom when choosing variable names? Because the symbol doesn’t actually matter! After all, it’s just a symbol. If the symbol we used to represent the idea of the quantity 2 had since time immemorial actually been the numeral “3” and vice versa, math wouldn’t be any different because the values of the numbers would have the same underlying meaning. All of which is to say that you are free to use whatever variable names you like.

• Audio
• Audio
• Audio
• Audio

• Audio
• Audio
• Audio
• Audio