Answer
a. 4
b. 6
c. 4
d. 4
Work Step by Step
if there are only zeros after a comma or if you have read left to right for nonzero numbers, stop there, you found the answer.
If there is a decimal point and only zeros come after the decimal point, include them in your count
however, if there are nonzero numbers after the zeros after the decimal point (what a mouthfull there) then only count the nonzero numbers at the end