The tableau below the division problem
shows all the non-null subtractions in the problem. The empty boxes will contain 10 on the left if a borrow was required and a 1 on the right if a loan was required.
Puzzles can be fun and entertaining, but if there's a way to get students involved in
(possibly enjoying the process of)
honing their problem-solving skill, they're invaluable. Such as "Long Division Puzzles":