Choose three C43 cards from four cards, and then each card has two numbers, one * * * three cards, so there are three C2 1. The last three cards are all in A33, so it is C43 * 3 * C21* A33 =192.

Now, 6 is used as 9. In order not to repeat the last card, there must be 9 in the card, and the remaining two cards are selected from those three cards, that is, C32. The same two cards have positive and negative numbers, so there are two C2 1, and the last nine cards and those two cards are ranked in A33, so it is C32 * 2 * C2 1 * A3.

So there are 192+72=264 different three digits.

I hope I can help you (* _ _ *) Thank you ~