There are 3 significant digits in 20.0
One
4
The logarithm to the base ten of 200 is 2.301 to four significant digits.
It has two significant digits.
3 significant digits.
It has 3 significant digits.
4 significant digits.
Five. All nonzero digits are significant and zeros in between significant digits are significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
000203 has 3 significant digits.