To create the largest number possible using the digits 0-9 each only once, we can arrange the numbers and apply operations creatively.
If we just concatenate the digits in descending order, we get:
9876543210
If we are allowed to use operations—like addition, multiplication, etc.—it can help maximize the outcome. However, simply concatenating the digits gives a straightforward highest result.
Considering the order of operations can lead to different results when combined with multiplication and addition. The best way without constraints is simply to concatenate.
Therefore, the largest number possible using each digit 0-9 exactly once is:
9876543210