Five
231.57 has five significant figures/numbers. All the numbers in 231.57 are significant.
The figure 18.03 has a total of four significant numbers
Because 10.00400 is 10.004, this has five significant digits (numbers).
Three. All nonzero numbers are significant, and any zeros in between significant numbers are significant.
Two significant figures.
3 significant figures.
There are 5 significant figures.
There are 5 significant figures.
3 significant figures.
3 significant figures.
One significant figure.
3 significant figures.