When people hear “robotics coding,” they think of expensive kits. But the best tool for a first lesson is a board, a piece of chalk, and a volunteer student.

Goal of the lesson

Students realize that a robot only does the commands it is given, in the order it is given, and they find and fix a mistake in a sequence of commands.

Preparation (5 minutes)

1. Draw a 4×4 grid in the middle of the room, or mark it with tape.
2. Place the student who will be the “robot” in one corner and a target (an eraser, for example) in another.
3. Write three commands on the board: Forward, Turn right, Turn left.

Activity (25 minutes)

Groups write the sequence of commands that will take the robot to the target. The robot student does only what is read aloud: no guessing, no helping.

On the first tries the robot will probably end up in the wrong place. That is the most valuable moment of the lesson: debugging. The group finds which line of the sequence is wrong and fixes only that line.

Wrap-up (10 minutes)

• Which group had the shortest sequence? Was there an even shorter route?
• Why did the robot “not understand”? When can machines not guess the way we do?
• How can we shorten commands that repeat? (A first step toward the idea of loops.)