When expressing the number 157 in scientific notation, what is the power of 10 used?

• A. 3
• B. 0
• C. 1
• D. 2

Answer: (D)

Verified step by step guidance

1. Understand that scientific notation expresses a number as a product of a number between 1 and 10 and a power of 10, in the form \(a \times 10^{n}\), where \$1 \leq a < 10\( and \)n$ is an integer.
2. Identify the original number, which is 157, and determine how to rewrite it so that the coefficient \(a\) is between 1 and 10.
3. Move the decimal point in 157 two places to the left to get 1.57, which is a number between 1 and 10.
4. Since the decimal point was moved two places to the left, the power of 10 will be positive 2, because moving the decimal left corresponds to multiplying by \$10^{2}$.
5. Write the number in scientific notation as \$1.57 \times 10^{2}$, confirming that the power of 10 used is 2.