Select the best answer for the question.
6. Which of the following is the same as $8.4 \times 10^2$?
A. 8,400
B. 840
C. 84
D. 8.4
Answer (1)
Multiply 8.4 by 1 0 2 , which equals 100.
Calculate 8.4" , " t im es 100 by moving the decimal point two places to the right.
The result is 840.
The correct answer is 840 .
Explanation
Understanding the Problem We are given the expression 8.4" , " t im es 1 0 2 and asked to find an equivalent value from the options A. 8,400, B. 840, C. 84, D. 84.
Plan of Action To find the equivalent value, we need to multiply 8.4 by 1 0 2 . Since 1 0 2 = 100 , we need to calculate 8.4" , " t im es 100 .
Performing the Calculation Multiplying 8.4 by 100 is the same as moving the decimal point two places to the right. So, 8.4" , " t im es 100 = 840 .
Selecting the Correct Option Comparing our result, 840, with the given options, we see that option B matches our result. Therefore, the correct answer is B. 840.
Examples
Understanding scientific notation is crucial in fields like physics and chemistry, where very large or very small numbers are common. For instance, the speed of light is approximately 3" , " t im es 1 0 8 meters per second. This notation simplifies calculations and makes it easier to compare values. Similarly, in computer science, large file sizes or memory capacities are often expressed using powers of 2, which can be related to scientific notation for easier comprehension.
