Computers follow instructions
Computer Science · Key Stage 1 · The School
Machines that obey
A computer is a machine that follows instructions EXACTLY. It is not clever on its own — it cannot guess what you meant. If you tell a robot "walk forward" but forget "stop at the wall", it walks into the wall. The instructions are called a PROGRAM.
Order matters
Try these teeth-brushing instructions: 1) brush your teeth, 2) put toothpaste on the brush. Wrong order — you brushed with a dry brush! A computer would do exactly that, because it follows the SEQUENCE it is given, step by step, never skipping ahead.
Be the robot
A brilliant game: one person is the robot, one gives instructions to cross the room. "Two steps forward. Turn left. Three steps forward." The robot does ONLY what is said. You will discover instantly how precise instructions must be — that discovery is the start of programming.
Instructions for getting ready for school: 1 put on shoes, 2 get out of bed, 3 eat breakfast, 4 get dressed, 5 brush teeth, 6 leave the house. Follow them EXACTLY, in that order, and you put shoes on in bed and get dressed after breakfast. Now reorder them. Nothing was wrong with any single instruction — the order was the bug, and that is true of most programs too.