I'm reading my physics book and I found something confunsing. In one place my book says that 10,3 km have 5 significant digits (I concluded that is because 10,3 km is 10 300 m ) and in one place it says that 576 km/h has also 3 significant digits. Is it because km/h? How many significant digits has 576 km/s? (3 or 6 (576 000 m/s))? Thx for your replay.