Answer:
Answer A (6.23*10^12) is the greatest number by far.
Step-by-step explanation:
Each of the four given numbers involves a power of 10, as follows:
10^12, 10^8, 10^(-6) and 10^3.
10^12 is by far the largest number.
Thus, Answer A (6.23*10^12) is the greatest number by far.
