Warm Up (15 min)

Introduction

Gather the class together and ask two volunteers to walk straight in some direction in the classroom. If they encounter a chair out of place, they must step over it. If they reach a wall, they must sit down.

Once all of the students are sitting down, ask how you would program a robot to respond to a wall or a chair. Remind students that you cannot simply say "Step over chair" unless you know there is a chair, and you will not always know there is a chair. It might be helpful to translate the task into instructions like:

• while there is a path ahead
  • walk forward
  • if there is a chair, step over it
• sit down

Tell students they will be using conditionals during this lesson. Give the definition of:

• Condition: A statement that a program checks to see if it is true or false. If true, an action is taken. Otherwise, the action is ignored.
• Conditionals: Statements that only run under certain conditions.

Open up a discussion of when you might use a conditional in your code.

Main Activity (30 min)

Online Puzzles

Students are in for a real treat with this lesson. It's likely most of your students have heard of Minecraft, but give a brief introduction for those that may not know.

Minecraft is a game of cubes. You can play as Alex or Steve as you work through mazes. You'll need to avoid lava, pick up items, and explore in a world made up of cubes of things.

Demonstrate one of the puzzles to the class (we recommend puzzle 11.) Once all questions have been addressed, transition students to computers and let them start pair programming.

Wrap Up (15 min)

Journaling

Having students write about what they learned, why it’s useful, and how they feel about it can help solidify any knowledge they obtained today and build a review sheet for them to look to in the future.

Journal Prompts:

• Draw a feeling face to show how you felt during today’s lesson.
• Draw something else you could have built in this minecraft world.
• Can you draw a scene where someone is using a conditional?

Extended Learning

More Minecraft

If you find that your class really enjoys the Minecraft environment, here are some links to other Minecraft games they can play online. These games will also teach basic coding skills.