Final answer:
To order the given numbers from smallest to largest, note that 4.5 x 10^-20 is the smallest as it has a negative exponent, followed by 9.47 x 10^8, then 12.57 x 10^7, with 7.8 x 10^20 being the largest.
Step-by-step explanation:
To order the numbers from smallest to largest, we must recognize that numbers with a negative exponent in scientific notation are less than one. With this in mind, the order from smallest to largest is:
- C. 4.5 x 10^-20 (Smallest)
- D. 9.47 x 10^8
- A. 12.57 x 10^7
- B. 7.8 x 10^20 (Largest)
Remember that the larger the exponent of 10, the larger the number. Also, a number with a negative exponent of 10 is a fraction of 1, making it much smaller than numbers with positive exponents.