In significant figures, which statement is correct about trailing zeros?

Trailing zeros are the zeros that appear at the end of a number after a decimal point. The statement that they are always significant if there is a decimal point is correct. This is because trailing zeros in a decimal number indicate precise measurement and contribute to the accuracy of the value being expressed.

For example, in the number 5.50, the trailing zeros signify that the measurement is accurate to two decimal places. Conversely, in a whole number like 1500 without a decimal point, the significance of the trailing zeros can be ambiguous because it is unclear whether the zeros are placeholders or if they reflect precision.

Therefore, when a decimal point is present, any trailing zeros serve to denote the precision of the number, thereby making them significant. This understanding is crucial in scientific contexts where accurate measurements are reported.