Four - the last zero is not significant.
* * * * *
Unfortunately, that is not true. Integers ending in 0 are ambiguous cases.
It is not possile to tell whether the number is accurate to the nearest integer (5 sig digs) or rounded to the nearest 10 (4 sig digs).
Five
3 significant digits because first zeros are just placeholders
Three. All nonzero digits are significant and zeros in between significant digits are always significant.
3
There are 4 significant figures in 6.741.
Three - all nonzero digits are significant.
5 of them.
Five
4
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.