12. (10 points) From five number cards $0, 2, 4, 6, 8$, select 3 different cards to form a three-digit number. How many different three-digit numbers can be formed (6 when flipped is 9)?


【Solution】Solution: According to the analysis,
Select 3 different cards from $0, 2, 4, 6, 8$ to form a three-digit number, which can form: $4 \times 4 \times 3=48$ (numbers); when 6 is flipped to become 9, then 9 in the hundreds place can form: $1 \times 4 \times 3=12$ (numbers);
9 in the tens place can form: $3 \times 1 \times 3=9$ (numbers);
9 in the units place can form: $3 \times 3 \times 1=9$ (numbers);
In total: $48+12+9+9=78$ (numbers);
Answer: A total of 78 different three-digit numbers can be formed (6 flipped is 9).
Therefore, the answer is: 78.