There are two significant figures in the measurement 0.0039.
There are three. The 4, the 5 and the zero in between. The two last zeros serve only to properly space the decimal point which, in this number, is implied.
300.9
There are three significant figures in 43.0. The zero at the end of the number is considered significant because it serves to specify the accuracy of the measurement to the tenths place.
4.884 has four significant figures and 2.25 has three significant figures. 4.884 x 2.25 = 10.989 = 11.0 rounded to three significant figures. When multiplying or dividing, the result must have the same number of significant figures as the number in the problem with the fewest significant figures.
Three significant figures would be 29.5cm.
3.738mL, when rounded to three significant figures, is 3.74mL
29.5 cm
It is: 29.5 cm
It rounds to 3.74mL
16.558 rounded to three significant figures is 16.6
0.00721004 rounded to three significant figures is 0.00721
44.981 rounded to three significant figures is 45.0
0.00858345 rounded to three significant figures is 0.00858
1,399.54 rounded to three significant figures is 1.40e3
79,966.92 rounded to three significant figures is 8.00e4
0.00721004 rounded into three significant figures is 0.00721