Summary
Highlights
Binary numbers typically increase in value when any '1' is added. This raises the question of how to represent negative numbers if adding '1' always makes a number positive.
There are two main methods for representing negative numbers in binary: sign and magnitude, and two's complement. This video focuses on the sign and magnitude method.
In sign and magnitude, positive numbers start with a '0' and negative numbers start with a '1'. The leftmost bit, known as the Most Significant Bit (MSB), becomes a 'sign bit' rather than contributing to the numerical value.
Because the MSB is used as a sign bit, it no longer holds a weighted value. This means that for an 8-bit binary number, the largest positive number that can be stored is +127, but it also allows for the representation of negative numbers from -1 to -127.