Question: are all zeros after a decimal significant?
Answer: Leading zeros (zeros before non-zero numbers) are not significant. ... Trailing zeros in a number containing a decimal point are significant. For example, 12.2300 has six significant figures: 1, 2, 2, 3, 0, and 0. The number 0.000122300 still has only six significant figures (the zeros before the 1 are not significant).