93000000 has 2 sig fig.
2
Two. The zeros are just placeholders.
231.57 has five significant figures/numbers. All the numbers in 231.57 are significant.
One
It is 93000000
The figure 18.03 has a total of four significant numbers
Three. All nonzero numbers are significant, and any zeros in between significant numbers are significant.
Because 10.00400 is 10.004, this has five significant digits (numbers).
3 significant figures.
It has five significant figures.
7 significant figures.
3 significant figures.