The rightmost column is the product shown in the middle column. From top-to-bottom, those numbers will be 83.1, 831 (given), 8310.
The middle column is a re-write of the first column and is equal to the third column. You can figure the numbers there from either direction. In the center row, you need 8.31 × ___ = 831. It should not be difficult for you to figure out the number in the blank is 100. (It is also the power of 10 between 10 in the first row and 1000 in the third row.)
The divisor in the first column is the inverse of the multiplier in the second column. 0.1 = 1/10, 0.01 = 1/100, and in the third row, 0.001 = 1/1000. The missing number in the first column is 0.001.
_____ The four missing numbers are 83.1, 100, 0.001, 8310. (top to bottom, left to right)
