You should be able to…

  • Explain why data is represented in computer systems in binary form
So that computers can be based on logic circuits. Each part of the circuit can be in one of two states 0 and 1/true or false
  • Understand and produce simple logic diagrams using the operations NOT, AND, and OR
  • Produce a truth table from a given logic diagram

TOPIC OVERVIEW (Test your knowledge)

NOT Gate

Not Gate

A NOT gate has just one input. The output of the circuit will be the opposite of the input. If 0 is input, then the output is 1. If 1 is input, then 0 is output.

Truth Table (Part Completed)

Not Gate 1

AND Gate


An AND gate can be used on a gate with two inputs. AND tells us that both inputs have to be 1 in order for the output to be 1.

Truth Table (Part Completed)

And Gate 1

OR Gate


The OR gate has two inputs. One or both inputs must be 1 to output 1, otherwise it outputs 0.

Truth Table (Part Completed)

OR Gate 1

Lesson Resources

  1. In your book create a ‘Truth Table’ for each of the logic gates shown above. Use the part completed tables above and ‘The Logic Lab’ interactive website to help you do this. Once complete have a go at the ‘real’ exam questions below…
  2. Test your knowledge with the following Exam Questions.
  3. Now have a go at this Scratch Game.

Exam Questions

Binary Logic Exam Questions

Marking Scheme

Marking Scheme