I am expecially having problems subracting with there is a borrow involved.
1001 - 10101010 (9 base 10 - 170 base 10)
If you want to subtract a larger number from a smaller number (giving a negative result) then the process is slightly different.
Step 1: Reverse 0 and 1s in 2nd binary ...
This job features binary subtraction and division.