Binary+Logic

=Binary Logic (Double lesson)=

Lesson Objectives
Understand why computers use binary logic Explain simple logic using AND, NOT, OR

Starter (5 mins)
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Homework - Due Next Friday
Complete the logic sequences & Truth tables on the attached document......



Task (10 mins)

 * NOT**

IF a switch is NOT on then output is TRUE

In a truth table it is usual to use Algebraic variables A, B, C...... for inputs and P, Q, R.......for outputs

Truth Table for NOT Click this link to create your own NOT circuit - screenshot it to word and create the truth table to go with it....

Task (10 mins)

 * AND**

The AND gate has 2 inputs. If **both** inputs = true then output = true

Truth Table for AND

Create your own AND circuit

Task (10 mins)

 * OR**

IF one OR both inputs = true then output = true

Truth Table for AND Create your own OR circuit

**TASK (10 mins)**
In a computer there are many circuits and logic gates will combine to form them.

A common one is a NAND gate which is an AND gate followed by a NOT gate.

The truth table uses the output of the AND as the input to the NOT gate

Create your own NAND circuit

Task (20 mins)
We use Boolean Algebra to write down these circuits. The NAND circuit above would be written like this
 * Boolean Algebra**

P=(A AND B) OR C

As with normal equations the first part is indicated in brackets.

Try and create a logic circuit and truth table for this equation - save your work in a word processor document

Q =(A OR B) AND C

Task (20 mins)

 * 1) Research Boolean and find out how it was named - add this information to your document
 * 2) Research the von Neumann principal - add this information to your document

Plenary (5 mins)
Why do you think computers use binary logic?