Three. All non-zero digits are significant, as are zeroes between them, and zeroes after a decimal point. The entire question about sigfigs is "what digits can you be confident are not rounded off?" The answer is three because you cannot prove that this is not rounded to the nearest hundred. You can only be sure that the three digits (405) are all correct and even the 5 might be rounded off. If it were 40500.0, then all six digits would be SigFigs because that is showing exactness. ■
The number 0.30 has two significant figures.
The number 3,072 has 4 significant figures.
Three - all nonzero digits are not significant.
There are 4 significant figures in 0.0032. Seems to be only 2 significant figures in this number.
2370.0 has five significant figures. The zero at the end of the number is significant because it's a part of the measurement accuracy or precision.
Three significant figures are in this number.
3 significant figures.
There are 4 significant figures in this number.
There are 4 significant figures in this number.
There are 3 significant figures in this number.
There are 2 significant figures in this number.
There are 3 significant figures in this number.
There are 3 significant figures in this number.
There are six significant figures in this number (i.e. all the figures here are significant).
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
There are 4 significant figures in this number.
There are 3 significant figures in this number.