The number of possible options for each digit in the PIN number is 10 (from 0 to 9). Since Sean needs to choose a 6-digit PIN number, he has 10 options for each of the six positions.
To find the total number of different possible PIN numbers, we can use the multiplication principle.
The total number of possibilities for a 6-digit PIN number is found by multiplying the number of options for each digit together:
\[ \text{Total number of possible PIN numbers} = 10 \times 10 \times 10 \times 10 \times 10 \times 10 \]
\[ \text{Total number of possible PIN numbers} = 10^6 \]
Therefore, Sean can choose from \(10^6\) different possible 6-digit PIN numbers for his online banking account. In mathematical terms, that equals 1,000,000 possible PIN numbers.