Using Bar Numbers

Say we have 444 - 286. This can be written as 2 bar 4 bar 2. So 2 bar 42 can be written as 158(all from 9 last from 10 rule). This allows you to do subtractions with having carry numbers.
Try 6767 - 1908 = 5 bar 2 6 bar 1= 4859. Try these yourself 804 - 388.