To calculate the total number of different 6-digit lottery tickets that can be sold when the order of the digits matters and all digits from 0 to 9 are available, we can use the concept of permutations.
Since each digit can range from 0 to 9, there are 10 possible choices for each of the 6 positions in the ticket.
Thus, the total number of different 6-digit combinations is calculated as follows:
\[ 10 \times 10 \times 10 \times 10 \times 10 \times 10 = 10^6 = 1,000,000 \]
Therefore, the total number of different lottery tickets that could be sold is 1,000,000.