10. (12 points) If the sum of the digits of a natural number $a$ equals 5, then $a$ is called a "Dragon Soaring Number". Arrange all "Dragon Soaring Numbers" in ascending order, and 2012 is the $\qquad$th number in this sequence.
10. (12 points) If the sum of the digits of a natural number $a$ equals 5, then $a$ is called a “Longteng number”. Arrange all “Longteng numbers” in ascending order, and 2012 is the 38th number in this sequence.
【Solution】Solution: According to the problem,

Enumerate the so-called “Longteng numbers” less than or equal to 2012:
One-digit numbers: 1, which is 5.
Two-digit numbers: 5, $14, 23, 32, 41, 50$.
Three-digit numbers: $104, 113, 122, 131, 140, 203, 212, 221, 230, 302, 311, 320, 401, 410, 500$.
A total of 15.
Four-digit numbers: If the first digit is 1, then the sum of the other digits is 4.
$103, 112, 121, 130, 202, 211, 220, 301, 310, 400$ and also $004, 013, 022, 031, 040$.
If the first digit is 2, there is 2003.
Before 2012, there are $1+5+15+15+1=37$.
Therefore, the answer is: 38