Question

what rules should you follow when adding and subtracting? check all that apply.

the exponents in scientific notation should be added or subtracted.
the exponents need to be the same so the leading numbers can be added or subtracted.
the result has the same number of decimal places as the least precise number.
the result has the same number of significant figures as number with the fewest significant figures.

Explanation:

Analyze scientific notation rules

When adding or subtracting numbers in Scientific Notation, the exponents must be identical so that we can add or subtract the leading coefficients directly. We do not add or subtract the exponents themselves. Therefore, the second statement is correct, and the first statement is incorrect.

Analyze significant figure rules

When performing addition or subtraction, the precision of the final result is determined by decimal places, not the total number of significant figures. Specifically, the result must be rounded to match the same number of decimal places as the least precise measurement (the value with the fewest decimal places). Therefore, the third statement is correct, and the fourth statement is incorrect (which applies instead to multiplication and division).

Answer:

• The exponents in scientific notation should be added or subtracted.
• The exponents need to be the same so the leading numbers can be added or subtracted. (Correct answer)
• The result has the same number of decimal places as the least precise number. (Correct answer)
• The result has the same number of significant figures as number with the fewest significant figures.