Why does a robot need us to tell it each step?

Have you ever heard a toy robot roll across the floor? Whirr, beep, blink! Its little wheels hum as it goes.

To make a toy robot move, someone has to tell it what to do. Roll forward. Turn. Stop. So why does a robot need us to tell it each step?

Inside a toy robot sits a tiny computer. The computer tells the wheels when to spin and when to rest. That way the whole robot can move.

But the computer needs something to follow. People write it a program, which means a list of steps for the robot to do. They write the program so the robot knows what comes first and what comes next.

The robot follows its program one step at a time, in order. It rolls forward when the program says roll. It turns when the program says turn.

A robot cannot guess the next step by itself. You can look at your blocks and guess what to do with them. The robot does not know what a block is, or what you want.

So the robot only does the steps in its program. Let's say the program says roll forward, but nobody wrote stop. What do you think the robot will do?

It keeps on rolling, all the way until it bumps the sofa. Bonk! So we add a stop step to the program, and now it stops right beside the sofa.

With every step written down, the robot can do the whole job. It rolls, it stops, it turns, and it pushes a block to you. Each step was there, so nothing got missed.

Program. People write every step in a program, because a robot cannot guess a step.

Well done for thinking like a real robot builder today, sweet one.