The rule when rounding off numbers is "If the first figure to be discarded is 5 or more then the previous figure is increased by 1". When 16490 is rounded off to 2 significant figures then the first figure to be discarded is 4. As this is less than 5 then the previous figure (6) is not increased by 1. 16490 to 2 significant figures is 16000.
8 By definition, all the figures are significant (no rounding off appears to have taken place). There are eight significant figures.
45.0 is the 44.981 to 3 significant figures.
0.00755 Any zeros that are before an additional number do not count. Thus, "0.00" would not count as significant figures. The first significant figure is the "7", with the "5" following it. With the second five (in my answer), "4" was rounded up to "5" because the number behind the "4" was a "6", thus the "4" rounds up.
To write 1042 L to two significant figures, you'll need to use scientific notation. It can't be 1000 L, because that has only one significant figure, because trailing zeros with no decimal point are not significant. To write 1042 L to two significant figures, you need to write it as 1.0 × 10³ L.
0.6942 rounded off to 2 significant figures is 0.69
7.0001 rounded off to 4 significant figures is 7.000
155cm rounded to two significant figures is 160cm
111.009 mm rounded off to four significant figures is 111.0
The answer is 0.059 as the four significant figures are 0,0,5,9.
The correct representation when the number 0.007225 is rounded off to three significant figures is 0.00722
9.95
600
8840
It is: 0.0024
599
1.0e6