Advanced formula to show number movement

Hi,

I am looking for a formula to represent the difference between digit movement, the lowest difference would be 0 and the highest 5 the result would be taken from 2 columns eg.
A    B
7    16 = that would equal the difference between digits 7 and 6 (first digit in column "B" is always ignored) in this case the result = 1
example 2
A  B
2  19 = 3 (in this case the difference is 3 digit movement in direction that would not go beyond 5 otherwise the result would be 7 which is above 5 and as I mentioned before the highest diference is 5

In conclusion:
we take in consideration digits between 0-9  so for example:
(0) (0) = movment difference 0,  (0) (9) = 1,  (1) (9) = 2 ,  (2) (9) = 3,  (3) (9) = 4,  (4) (9) = 5 (5) (9) = 4, (0) (5) = 5 , (0) (6) = 4  and if there are two digits in a column the first one is always ignored so here is the example:
(0) (19) = 1,  (1) (29) = 2 ,  (2) (59) = 3,  (3) (49) = 4,  (34) (9) = 5 (15) (39) = 4, (10) (55) = 5 , (50) (56) = 4
I hope I have managed to explain this properly.
What would be the formula to do this in Excel?

Many Thanks,

Regards,

Peter