Why does 3000 have only 1 significant figure but 30.0 has 3 significant figures?
See: significant digits are independent of units.e.g. 30m = 0.03km = 3000cm all will have only 1 significant digit.A zero after decimal indicates that measurement is more accurate.e.g. 30.0m (all 3 digits are significant or important because there's a zero after decimal.)30m - 1S.D.30.0m - 3S.D. (better measurement)30.00m - 4 S.D.(even better)
cause we don't know what the other digits are.... people say light goes 300000000 m/s, but they're rounding, somewhere.