Four
2 of them.
The figure 18.03 has a total of four significant numbers
5 significant figures.
4 significant figures.
Two
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.
There are 5 significant figures.
Two significant figures.
Four significant figures.
Four significant figures.
Three significant figures.
It has 4 significant figures