4 significant figures.
4 significant figures.
One significant figure.
Four significant figures.
There are three of them
5 significant figures.
2 significant figures.
4 significant figures.
4 significant figures.
Two significant figures.
There are 5 significant figures in this number.
Three significant figures: 1,2,1.
1 significant figure.
One significant figure.
Four significant figures.
3
Six of them