State the number of significant figures.

Question

1) 809 Answer : 3

2) 0.0060 Answer : 5?

3) 0.00000095 Answer : 9?

4) 5.60 Answer : 3

5) 5.743 Answer : 4

6) 0.010 Answer : 4?

Answer 1

2, 3, 6 are wrong: Zeroes to the left of significant digits are NOT significant, unless they are between two non zero digits.