Download Class A2 IGCSE Computing Chapter 32 Number Bases

Take 12 and convert to Binary (8 bits) – 0000 1100
-12 would be
-- 11110100
The one in the beginning denotes it is a negative number.
Rules : 1- Flip the digits and add 1
Or 2 – Starting from right leave all the digits alone upto and including first
‘1’. Change all the other digits.
Converting -12 to 12 is also similar
1111 0100
-12
0000 1011
+
1
0000 1100
12
Or leave all digits alone till first 1. Change the rest.
Converting a 2s complement into Denary
Consider this number : 1001 0111
Put it under the respective heads here and get the resultant Denary number
-128 64 32 16 8 4 2 1
1
0 0
1 0 1 1 1
This equals : -128 + 16 + 4 + 2 + 1 = -105
Binary Subtraction
2