9514 1404 393
Answer:
3 significant digits
Explanation:
If there is a decimal point with non-zero digits to its left, all digits to the right of the left-most non-zero digit are significant. Here, that is all of them. This number has 3 significant digits.
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Comment on other cases
If there is no decimal point, the digits between any leading and trailing zeros are significant. For example, 02000 has 1 significant digit.
If there are no non-zero digits left of the decimal point. All digits except leading zeros are significant. 0.0031000 has 5 significant digits.