Which of the following is a rule for determining significant figures in a measured number?

• A. All digits in a number are always significant.
• B. All nonzero digits are always significant.
• C. Leading zeros are always significant.
• D. Trailing zeros in a number without a decimal point are always significant.

Answer: (B)

Verified step by step guidance

1. Understand that significant figures (sig figs) are the digits in a number that carry meaningful information about its precision.
2. Recall the basic rule: All nonzero digits are always significant because they represent measured values.
3. Recognize that leading zeros (zeros before the first nonzero digit) are not significant; they only indicate the position of the decimal point.
4. Know that trailing zeros in a number without a decimal point are not necessarily significant; their significance depends on the context or notation (such as scientific notation).
5. Conclude that the correct rule among the options is: All nonzero digits are always significant.