pxt-calliope/docs/courses/csintro/conditionals/overview.md

# Introduction

Computer programs are instructions telling the computer how to process input and deliver output. 
An important part of programming is telling the computer WHEN to perform a certain task. 
For this, we use something called ‘conditionals’. Conditionals get their name because a certain Condition or Rule has to be met.

Students are all already familiar with the concept of conditionals in their daily lives!

Have they ever had their parents say..?
* “If you clean your room, you can go out with your friends.”
* “If your homework is done, you can play video games.”
* “If you do your chores all week, you get your allowance, else you are grounded.”

These are all conditionals! Conditionals follow the format of IF this, THEN that.
>**IF** (condition is met), **THEN** (action performed)

Have the students share a few conditionals from their own lives with the class or within small groups.

Note: For older students, you can have them add the ELSE portion of a conditional.
>**IF** (condition is met), **THEN** (action performed), **ELSE** (different action performed)

Example:
* IF it is snowing, THEN wear boots, ELSE wear shoes.

The ELSE portion makes sure that a different action is performed in either case. Without the ELSE action, your students might be barefoot! 

![If-Then workflow](/static/courses/csintro/conditionals/flowchart.PNG)

Tell the students that they will be acting out some conditionals as though the whole class is a computer program for a game. Each student will perform a described action if the indicated condition is met. 

**Note:** This activity can be done as a whole class or in smaller groups or as a pencil and paper activity.