Which statement correctly defines scientific notation?

• A. A number expressed as a decimal with a fixed decimal point
• B. A number written as a fraction of two integers
• C. A number written as the product of a coefficient and 10 raised to a power
• D. A number expressed in binary form

Answer: (D)

Scientific notation expresses a number as the product of a coefficient and a power of ten. This format makes very large or very small numbers easier to read, compare, and work with. The coefficient is a number between 1 and 10 (in magnitude), and the power of ten shows how far to move the decimal point. For example, 320,000 is written as 3.2 × 10^5, and 0.00456 is 4.56 × 10^-3. This is different from writing a number as a fixed decimal, or as a fraction, or in binary form. So the defining idea is a number written as the product of a coefficient and ten raised to a power.