Question

Which of the following denotes the scientific notation of the number $172,900?$

• A. $1.7\times {10}^5$
• B. $1.72\times {10}^6$
• C. $1.729\times {10}^5$
• D. None of the above

Answer 1

The correct option is C $1.729\times {10}^5$

Scientific notation:
Scientific notation is a form of presenting very large numbers or very small numbers in a simpler form.

The scientific notation of a number looks like:

Where

• $1\le A<10$
• $B:$
  • Positive integer equals to the number of places decimal point moves towards left.
  • Negative integer equals to the number of places decimal point moves towards right.

Finding scientific notation of 172,900

• Write $172,900$ as $172,900.0$
• Move the decimal to the left $5$ places; so it is positioned to the just right of the leftmost non-zero digit $1.$, i.e., $1.72900$
• Remove all the zeroes. Now, the number becomes $=\mathrm{1.729.}$
• Since the decimal is moved $5$ places to left, therefore, we use here a positive exponent $5.$
• Hence, $1.729\times {10}^5$ is the scientific notation of the number $172,900$.

Therefore, option (c.) is the correct one.