Praxis Core Academic Skills for Educators: Mathematics (5733)Number and QuantityEasy
A financial analyst is evaluating an investment. The value of the investment is 2.5 × 10³ dollars. What is this value in standard notation?
- A$250.00
- B$25.00
- C$25,000.00
- D$2,500.00
Show answer & explanationAnswer & explanation
Correct answer: D. $2,500.00
To convert scientific notation to standard notation, move the decimal point according to the exponent. A positive exponent means move right, and a negative exponent means move left.
Why the other options are wrong
- A. This would be 2.5 × 10².
- B. This would be 2.5 × 10¹.
- C. This would be 2.5 × 10⁴.
Scientific Notation to Standard
To convert a number from scientific notation (a × 10ⁿ) to standard notation, move the decimal point in the coefficient 'a' by 'n' places. Move right for a positive 'n' and left for a negative 'n'.
- Positive exponent (n > 0) means a large number; move decimal right.
- Negative exponent (n < 0) means a small number; move decimal left.
- The number of places to move the decimal is equal to the absolute value of the exponent.
Memory trick: Exponent's Sign Shows Decimal's Direction!