2 significant figures.
There are 3 significant figures in this measurement.
There are 2 significant figures in this measurement.
There are 3 significant figures in this measurement.
4
3 of them.
52.8005 mg to five significant figures is 52.801 mg.
3 of them.
2
3
0.050200 mg has 5 significant figures. The zeros before the 5 are considered significant when they come after a decimal point.
The four and the two fives.
5 To the tenth of a milligram = 5.0000 g