Question 25
An places the numbers $1$ to $9$ in a $3\times3$ grid, using each exactly once. He reads each of the three rows from left to right, each of the three columns from top to bottom, and each of the two diagonals from top to bottom, obtaining eight three-digit numbers. What is the smallest possible sum of these eight numbers? For the example grid shown, the eight numbers are $987,654,321,963,852,741,951,753$.
