After lots of Googling to try and understand what an exponent bias really means, I came across this video which explains it pretty well.
When someone talks about biasing the exponent, it means trying to represent negative numbers with positive numbers so you don’t have to put a negative sign in front. It is just a conversion or shift.
You’ll see in the video how 3 is shifted to 10 (by adding 7 which is half of the max number in a 4 bit representation).