Two. The zeros between the seven and six are significant.
There is only one significant: figure 6.
Remenber: LEFT zero's are NEVER significant!
Six
5.008
231.57 has five significant figures/numbers. All the numbers in 231.57 are significant.
3 significant figures.
2310 has 3 significant figures.
Three
Four
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.
There are 5 significant figures.
3 significant figures.
2 significant figures.
1 significant figure.
Two significant figures.
Four significant figures.