Remember this is written in hex, so the 101 in 0x101
are hex-numbers.
The last 1 in 0x101 is the hex-number 1 that
translates to binary 0001, this are the 4 last bits.
So if you want to write the whole 0x101 in hex it
would be something like 0x 0001 0000 0001
Hope I explained this so that it's possible for you to understand it ;-)