1. **Problem:** Find the least possible value of $m$ so that the number $81231m37$ is divisible by 9. 2. **Rule:** A number is divisible by 9 if the sum of its digits is divisible by 9. 3. **Sum of known digits:** $8 + 1 + 2 + 3 + 1 + 3 + 7 = 25$ 4. **Sum including $m$:** $25 + m$ 5. We want $25 + m$ to be divisible by 9. The multiples of 9 near 25 are 18 and 27. Since 18 < 25, the next multiple is 27. 6. Solve for $m$: $$25 + m = 27 \implies m = 27 - 25 = 2$$ 7. **Answer:** The least possible value of $m$ is $2$.