1. 4 significant numbers
2. 6 significant numbers
3. 3 significant numbers
4. 3 significant numbers
Further Explanation
Significant numbers are numbers obtained from the measurement results of exact numbers and the last number estimated
1. 19.99
all non-zero numbers are significant numbers
, so there are 4 significant numbers
2. 140486
a zero which is located between two non-zero numbers including a significant number
, so there are 6 significant numbers
3. 0.0609
a zero in front of a decimal point is not a significant number, so there are 3 significant numbers (6,0 and 9)
4. 5.08
Any zeros between two non-zero numbers are significant, so there are 3 significant numbers(5,0 and 8)
