OCR J277 2.4.1: Boolean logic
The free BugBot lessons that teach this point, a robot to try it on, and the past-paper questions that test it.
What it covers
Inside every processor are billions of tiny circuits called logic gates. Each takes one or two inputs that are on or off, 1 or 0, and produces an output that is on or off. Put enough of them together and you get a computer. This module goes inside BugBot's processor, and it starts with the gates.
- AND, OR and NOT
- Truth tables
- A robot decision as a circuit
- Three inputs
Or do it in the simulator, with tasks that mark themselves
Lessons that teach it
- F9.1 Logic gates and truth tables Logic and computer systems
AND, OR and NOT, their symbols and truth tables, and a robot decision as a circuit. - F9.2 Logic circuits and expressions Logic and computer systems
Combining gates, Boolean expressions, XOR, and the half adder.
Try it on a robot
The task from F9.1 Logic gates and truth tables, 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.
- OCR J277 June 2025 Paper 2, Question 5(a), (b): A logic circuit from a description, and the truth table for A AND B 5 marks
- OCR J277 June 2024 Paper 2, Question 5: A truth table for (A AND B) OR C and a circuit for NOT A AND (B OR C) 7 marks
- OCR J277 June 2022 Paper 2, Question 2(a): A logic diagram for (A OR B) AND NOT C, and what a truth table is for 6 marks
- Edexcel 1CP2 June 2025 Paper 1, Question 5(a) to (c): Computational thinking: a three-input truth table, a 2D array with a logic error, a factors trace table 10 marks
- Edexcel 1CP2 June 2023 Paper 1, Question 4: Computational thinking: trace tables and records, an odd or even flowchart, linear search, S AND M 20 marks
The specification is OCR's own document; this page says which of our lessons teach point 2.4.1 and is not endorsed by the board.