The number 40 has how many significant figures? Chemistry Measurement Significant Figures 2 Answers Catherine T. Mohs · EZ as pi Apr 18, 2017 Answer: #1# Explanation: It has one because the #4# is the significant digit and the #0# doesn't count. However, if you had #40.0#, you would have three, because the #0# after the decimal point and the #4# count and the numbers between the significant digits also count. Martin M. · EZ as pi Apr 18, 2017 Answer: There is only #1# significant figure in the number #40.# Explanation: Since there is no decimal point in the number, the trailing zero is not significant. Therefore the number #40# has only #1# significant figure. Related questions What are rounding and significant figures? How can I round significant figures when multiplying? How can I round significant figures in Excel? Why should I use significant figures in chemistry? Question #1cb75 When I am doing calculations, how much should I round of the masses in the Periodic Table? What are significant figures and why do they matter? Question #8372c Question #b65fe Question #0a2eb See all questions in Significant Figures Impact of this question 5040 views around the world You can reuse this answer Creative Commons License