OCR J277 2.1.1: Computational thinking
The free BugBot lesson that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
A delivery robot in a warehouse does one enormous job: collect orders and bring them to the loading bay. Nobody writes that as one enormous program. They break the job into smaller problems, and those into smaller ones, until each piece is simple. And they hide the details of each piece behind a name. Those two ideas are decomposition and abstraction, and they are how every large program is built.
- Decomposition: breaking a problem down
- Abstraction: hiding the details
- Building from the bottom up, testing as you go
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- F4.4 Decomposition and abstraction Functions and structured code
Structure diagrams, and hiding the details of a job behind a function.
Try it on a robot
The task from F4.4 Decomposition and abstraction, running here. Change the program and press Run.
Past paper questions on this
Real exam questions that test this, each worked through with a program you can run.
- AQA 8525 June 2025 Paper 1, Question 7: Read a subroutine: purpose, outputs, return value, parameter 7 marks
The specification is OCR's own document; this page says which of our lessons teach point 2.1.1 and is not endorsed by the board.