How many significant digits for 71.0 ? 3 2 1

Step 1 ：The number of significant digits in a number is the number of digits that carry meaningful information about its precision. In this case, the number 71.0 has three significant digits: the 7, the 1, and the 0 after the decimal point. The 0 after the decimal point is significant because it indicates a level of precision in the measurement.

Step 2 ：Final Answer: The number 71.0 has \(\boxed{3}\) significant digits.