Binary Addition

Addition [edit]

Let's look at an example of adding in decimal:

 25
+43
---
 68

This is pretty simple, we just add up each column, but what happens if we have can't fit the result in one column. We'll have to use a carry bit:

 98
+57
---
155
11

Hopefully you're good with that. Now let's take a look at how it's done in binary with a very quick example, with a check in denary:

 01010 (1010)
+00101 (510)
------
 01111 (1510)

This seems pretty straight forward, but what happens when we have a carry bit? Well pretty much the same as in denary:

 01011 (1110)
+00001 (110)
------
 01100 (1210)
   11

1010 + 0001

Answer :

 1010

+0001 ----

 1011

01001001 + 00110000

Answer :

 01001001 

+00110000

 --------

 01111001

01010100 + 00110000

Answer :

 01010100 

+00110000

 --------

 10000100

01001010 + 00011011

Answer :

 01001010 

+00011011

 --------

 01100101

01111101 + 00011001

Answer :

 01111101 

+00011001

 --------

 10010110

00011111 + 00011111

Answer :

 00011111 

+00011111

 --------

 00111110

10101010 + 01110000

Answer :

 10101010 

+01110000

 --------

100011010

Note we have some overflow, this will come in useful when doing subtraction