Final answer:
The student's question involves converting numbers to scientific notation, which makes very large or very small numbers easier to work with by moving the decimal point to create a new number between 1 and 10, multiplied by a power of 10.
Step-by-step explanation:
The question deals with expressing numbers in scientific notation. Scientific notation is a way to write extremely large or small numbers more compactly and is often used in subjects like chemistry and physics for convenience.
- For the number 123,456.78, the proper scientific notation would be 1.2345678 × 10⁵ because the decimal point is moved 5 places to the left.
- The number 98,490 in scientific notation is 9.849 × 10⁴, with the decimal point moved 4 places to the left.
- To express 0.000000445 in scientific notation, we move the decimal point 7 places to the right, so it becomes 4.45 × 10⁻⁷.
- The number 0.000552 becomes 5.52 × 10⁻⁴ after moving the decimal point 4 places to the right.
- For the number 1,987, scientific notation would be 1.987 × 10³ since the decimal point moves 3 places to the left.
- Finally, 0.00000000887 in scientific notation is 8.87 × 10⁻⁹ because the decimal point moves 9 places to the right.
When dealing with scientific notation and significant figures, always remember that precision is key, and consider the number of significant figures that carry meaning in your calculations.