There are 5. The zero is only ignored when it follows all other non-zero digits
If it were 14,520 - the 0 would not be significant ... because the figure could be 14,524 rounded down or even 14,515 rounded up. However, if it were 14,520.0, there would be 5, with the "uncertain" number being the trailing 0
5 significant figures.
there are 2 significant figures
There are four significant figures in 34.80 km.
There are 6 significant figures
3 of them.
2
3 of them.
It is the digit 2
3.774 is to 4 significant figures (count them)
1,000 m = 1 km If there is not decimal point at the end of 1000. it is just 1km. If there is a decimal point the correct significant figures would be 1.000 km
Assuming the final zero is not there for decorative purposes, 6 sig figs.
To round 12.555 km to four significant figures, you would keep the first four non-zero digits, which are 12.56 km since the next digit (5) is greater than 5.