Three.
5 significant figures.
there are 2 significant figures
There are 6 significant figures
4 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.
170.040 has six significant figures. A significant figure is any non-zero digit or any embedded or trailing zero. Leading zeros are not significant.
All of those figures are significant. If you want to round it to 2 sig figs, that would be 13.