You are probably familiar with variables in math. (“Solve for x: 2x + 4 = 3x”) In math problems, the goal is often to figure out the secret value of a variable. Once you figure it out, the problem is finished. Variables work differently in computer science:

• You can create them whenever you want. In fact, you already made one. Remember typing number = 5 above? You made a variable called “number” and set its value to 5. This is called declaring a variable.
• In computer science, you get to decide what value variables have, and you can change them whenever you want. This is called assigning values to variables. Try this:

>>> name = "Willie"
>>> "my name is " + name

• You can call them whatever you want (no spaces though!) In math, variables have names like x, y, and t. In computer science, we usually call them things like number_of_coins_in_my_hand or direction_my_character_is_facing because it’s less confusing.

You can think about variables as little boxes in your computer’s memory that store things so you can use them later.