Share a wonderful digital game

Share a wonderful digital game

 

First, calculate your pen according to the following rules,
1. Use 1, 2, 3, 4, 5, 6, 7, 8, 9 (excluding 0) to form a three-digit number;
2. The numbers in the three digits cannot be repeated and are from large to small, such as 731 (marked as 1 );
3. invert the three digits, such as 137 (marked as 2 );
4. Number 1-Number 2 = Number 3, for example, 731-137 = 594;
5. 3 to get 4, for example, 495;
6. Number 3 + number 4 = Number 5; for example, 594 + 495 = 1089;
7. The final result and number 5.
Based on the above rules, you can combine a three-digit number to see what the final result number is 5?

 

Is it 1089? If not, it would be too surprising!