5
Explanation:In order to be able to say how many sig figs are used for the measurement 811.40 g, you need to know that
non-zero digits are always significanta trailing zero that follows a decimal point and a non-zero digit is always significantIn your case, the measurement
811.40
has four non-zero digits and one significant trailing zero.
8,1,1,4→ non-zero digits8,1,1,0→ significant trailing zeroTherefore, you can say that this measurement has five significant figures
811.40→ five significant figures