Question

Scientific notation can be written in the general form as $a\times {10}^n$, where $n$ is an integer. Find the range of $a$.

• A. $1\le a<5$
• B. $1<a<10$
• C. $1<a\le 10$
• D. $1\le a<10$

Answer 1

The correct option is D $1\le a<10$

Scientific notation can be written in the general form as $a\times {10}^n,$ where $\underset{–}{1\le a<10}$ and $n$ is an integer.

For example, scientific notation of $78,000.0$ is $7.8\times {10}^4$ (moving the decimal point $4$ places to the left; exponent to the base $10$ is $+4$) not $78\times {10}^3$ because $78$ does not lie in-between $1$ and $10$.

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