I believe that the correct answer is: Eight hundred fifty two million three hundred sixty nine thousand one hundred sixty seven or 852, 369, 167. This is computed by adding ten million more to the original number or adding 1 to the 4 in between 8 and 2. This is because 4 is in the ten millions' place in the number provided. The trick is just to to figure out which digit you need to add the number to then to copy the rest down.