What are the number of significant figures in each of the following measured quantities?

Question

A) 358
B) 0.054
C) 6.3050
D) 0.0105
E) 7.0500 x 10^-3

Answer 1

A is easy, all nonzero digits are significant. I'll let you count.
B is a little more difficult. The zeroes only hold the place.(only indicate the magnitude of the number.) If zeroes are both to the right of a significant digit and to the right of a decimal, they are significant. These zeroes are not to the right of a significant figure. There are two significant figures in this problem.
C follows the rules stated above. All of the nonzero digits are significant, so that is three plus the zeroes. Since both zeroes are to the right of a significant figure AND to the right of the decimal, they are significant. This gives 5
D The zero between the 1 and the 5 is significant, the other zeroes are not.
E When using scientific notation, you only need to pay attention to the number, not to the 10 to the something. This number has the 7 and the 5 which are significant. All of the zeroes present are both to the right of a significant figure and to the right of the decimal. There are 5.

Answer 2

3
2
5(4th rule states that all figures on the right hand side of a decimal point are significant figures)
3
5

Answer 3

A = 3
B = 2
C = 4
D = 3
E = 3

Answer 4

3
3
4
4
5
if you wanna know the rules for writing the number of significant figures please write to me