Lesson 1: Getting Started
Lesson 2: Introduction
Lesson 3: Math
Math Basics
More Operators
More Division
Floats
Comparison Operators
Practice
Practice: Answers
Lesson 4: Strings
Lesson 5: Variables
Lesson 6: Errors
Lesson 7: Booleans
Lesson 8: Lists
Lesson 9: Logic
Lesson 10: Loops
Lesson 11: Functions
Lesson 12: Input
Lesson 13: Modules
Lesson 14: Games
Lesson 15: Minecraft
Lesson 16: Wrapping Up

Now it's time to start writing some instructions for computers!

The first thing you need to do is open a program called Idle. If you've followed the instructions from Lesson 1, it should be on your desktop or in your Applications folder.

Let's get started with some very simple math.

Go ahead and type these expressions one at a time. After each one, hit the Enter key and see what happens.

>>> 1 + 2 >>> 12 - 3 >>> 9 + 5 - 15

We're using some symbols you probably already know - the plus and minus signs. In the programming world, we call these **operators**.

Operators | |
---|---|

add | `+` |

subtract | `−` |

By the way, you have just started writing Python.

>>> 1 + 2 3 >>> 12 - 3 9 >>> 9 + 5 - 15 -1