Choose a starting number from 1 to 9 (or any range you prefer)
Write the grid with these rows: M A S H
Write the numbers 1 through 10 in the first row (or your chosen range)
For each letter row, cross out numbers based on the rule for that letter
M: Cross out multiples of 1 (every number)
A: Cross out multiples of 2
S: Cross out multiples of 3
H: Cross out multiples of 4
After completing all rows, the remaining number is the result
If you want a clearer outcome, repeat until only one number remains