Five, since the trailing zero should have been stripped out if it were not significant.
There are 4 significant figures in this problem.
231.57 has five significant figures/numbers. All the numbers in 231.57 are significant.
5 significant figures.
There are 3 significant figures in '4.50g'
The figure 18.03 has a total of four significant numbers
4 of them.
Three of them.
There are 4 significant digits
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).
There are 5 significant figures.
1 significant figure.