Topic Two (1.2): Binary Manipulation and Negative Numbers
This topic will firstly introduce you to addition involving two 8-bit binary numbers, by using four simple mathematical rules, and also to the concept of overflow – why denary numbers greater than 255 cannot be represented by 8-bit binary.
You will be introduced to the concept of logical binary shifts and explore how these can change the value of a binary number.
Finally, you will see how a technique called “two’s complement” can be used to represent negative binary numbers without requiring a minus sign. This is how subtraction is achieved in binary, by turning a number negative and adding it!
Read
Please read through and make notes on pages 16 to 20 in your coursebook.
Links
Please work through the following resources.
A simple guide to binary addition:
WATCH – How To Do Binary Addition (The Easy Way) (YouTube) Links to an external site.
A nice resource explaining logical binary shifts:
READ – What is a Binary Shift (Bits of Bytes) Links to an external site.
A short but useful explanation of logical binary shifts for those who would prefer to watch a video:
WATCH – Binary Logical Shifts (YouTube) Links to an external site.
A good video on two's complement and negative binary numbers:
A detailed written explanation:
READ – Negative Binary Numbers (All About Circuits) Links to an external site.