1. 10 Start from 1, write natural numbers in sequence, and ask what the number at the one millionth position is?
[Solution] Since there are 9 one-digit numbers, 90 two-digit numbers, 900 three-digit numbers, ..., and $900000 \times 6 > 1000000$. Therefore, the required digit is not in any seven-digit number. Also, because $9 + 90 \times 2 + 900 \times 3 + 9000 \times 4 + 90000 \times 5 = 488889$, the required digit must be in some six-digit number.
Since $\quad 1000000 - 488889 = 511111$,
$$
511111 = 6 \times 85185 + 1,
$$

Therefore, the required digit is the first digit of the 85186th six-digit number (i.e., 185185), which is 1.