1. Aberdeen Grammar School
Digital Electronics
Boolean Algebra
Aberdeen Grammar School

2. What is Boolean Algebra?
Boolean Algebra was created by the mathematician George Boole, back in the19th century.
What is Boolean Algebra?
It is a shorthand way of describing how a digital electronic circuit behaves.

3. So what does this ‘Boolean Algebra’ look like…
We start by looking at a logic gate, for example an OR gate. A Z B
We need to have labeled the inputs and the outputs with letters.

4. Z = A + B For this example, we wont need a truth table.
We can express the output Z, in terms of inputs, A, B, as follows: A Z B
Z = A + B
What are you thinking??

5. Z = A . B We can do the same for an AND gate… But this time… We say:
‘Z equals A AND B’ A Z B
Z = A . B

6. Z = A And the same for a NOT gate… For this we say: ‘Z equals NOT A’ A

7. What do you think? Wait… Are we missing any terms?
We will need truth tables later to tackle larger circuits.
Wait… Are we missing any terms?
What do you think?