Question

Write down the number of significant
figures in the following: 0.003 m²,
0.1250 gm cm2, 6.4 x 106 m, 1.6 x 10-19
C, 9.1 x 10-31 kg.
[Ans: 1, 4, 2, 2,2]​

Answer 1

Answer: 3, 4, 2, 2

Explanation:

Zero before the decimal point is not a significant figure.

Same for the second one. Zero after the decimal point is a significant figure.

For counting significant figures of the last two, you will neglect the power term and only count the significant figures of the preceding decimal number.