Sir!! In case we have to find the unit digit of the difference between two numbers, may we know what would be the final answer if the difference is negative??
That's a very good question, buddy! If you get the difference as negative, then you have to subtract it from 10. E.g. if you have to find 123456 - 369, the unit's place will be 6 - 9 = -3. So, the actual unit's place would be 10 - 3 = 7. Let me know if this is clear.
