1 of them.
1
3 significant figures.
There are 2 significant figures in this number.
There are 4 significant figures in this number.
1 of them.
1
Three significant figures are in this number.
3 significant figures.
Four, assuming that 7.000 is written in that form to indicate that it has 4 significant figures.
There are 4 significant figures in this number.
There are 2 significant figures in this number.
There are 4 significant figures in this number.
There are 3 significant figures in this number.
There are 3 significant figures in this number.
There are six significant figures in this number (i.e. all the figures here are significant).
There are 3 significant figures in this number.