Final answer:
To find the value of a mathematical expression and express it in scientific notation with the correct number of significant figures, use a calculator to obtain the initial value, then round and format the result according to the rules for significant figures.
Step-by-step explanation:
The student is asking to find the value of a mathematical expression and to represent it in proper scientific notation with a given number of significant figures. This type of problem requires knowledge of the rules for rounding and scientific notation, which is a common topic in high school mathematics. To handle such problems, you should first use a calculator to find the initial answer and then adjust it to comply with the rules for significant figures and scientific notation.
For example, if you calculate an expression like 456 × (7.4 × 10^8), you'll initially get a raw number from the calculator. From here, you need to round the answer to the correct number of significant figures and express the result in scientific notation. Scientific notation requires that the answer be presented in the form of a number between 1 and 10 multiplied by 10 raised to an exponent.
To follow the specific directions from the student, remember to pay attention to the number of significant figures the final answer requires, which might involve rounding up or down depending on the digits involved.