Place each of the digits 0 through 9, without repetition, in the boxes above. What is the maximum possible sum?

42

10656

To find the maximum possible sum, we need to place the digits in a way that maximizes their value in each column.

Since we want the maximum sum, we would want the largest digits in the leftmost columns and the smallest digits in the rightmost columns. Therefore, we can start by placing the digits from 9 to 0 in descending order from left to right.

Here's one arrangement that gives us the maximum possible sum:

9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0

Now, we can add up the digits in each column to find the maximum sum:

9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 + 0 = 45

Therefore, the maximum possible sum is 45.