**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**

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)

**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)

**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)

**Lesson Resources**

- 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…
- Test your knowledge with the following Exam Questions.
- Now have a go at this Scratch Game.

**Exam Questions**

**Marking Scheme**