# Addition

## Contents

# Overview

### CraignDave

Addition is covered from 0:00 until 5:46

https://www.youtube.com/watch?v=t15dhDG_WUA&list=PLCiOXwirraUDGCeSoEPSN-e2o9exXdOka&index=2 (0:00 - 5:46)

### Computer Science Tutor

https://www.youtube.com/watch?v=4wrBpIYimrw&list=PL04uZ7242_M6O_6ITD6ncf7EonVHyBeCm&index=4

# Binary Addition

Binary addition is being able to add two numbers together which are represented in binary form, which consist of 1s and 0s, you can add them together by converting them into denary, adding It together and then converting it back but its much faster to use the column addition method which you will see below.

There are four possibilities when adding binary numbers, these possibilities are:

a total of 0 (0+0) put down 0 a total of 1 (1+0, 0+1 or 0+0+carried 1) put down 1 a total of 2 (1+1) put down 0, carry 1 a total of 3 (1+1+ carried 1) put down 1, carry 1

For example, solve 6+7 using binary addition:

First convert 6 and 7 from denary to binary using your preferred method

6 = 4+2+0 = 110 7 = 4+2+1 = 111

Then add them keeping in mind the 4 possibilities and add each digit together, starting on the right:

110 + 111 ---

So:

0+1 = 1

1+1 = 0 carry 1

1+1+ carried 1 = 1 carry 1

1 + 0 = 1

so 110+111 = 1101. Converting this number back to denary gives us an answer of 13.

### Another Example

### Adding More Numbers Together

You could get 3 numbers to add however you wont be given a situation in which there are more than a total of 3.

For example:

101 101+ 011+ ----

Which would = 1101

If you do end up in a situation where you have more than 3 ones, you need to miss a column and place the carry in the next one.