How many significant digits is 0.02?
The Correct Answer and Explanation is:
Correct Answer: 1 significant digit
Explanation:
Significant digits (or significant figures) are the digits in a number that carry meaningful information about its precision. When determining the number of significant digits in a decimal number, follow a few key rules:
Rule 1: Nonzero digits are always significant.
These are digits from 1 through 9.
Rule 2: Leading zeros (zeros before the first nonzero digit) are not significant.
They only serve to locate the decimal point.
Rule 3: Zeros between nonzero digits are significant.
Rule 4: Trailing zeros (zeros after a nonzero digit in a decimal number) are significant.
Now let’s apply these rules to the number 0.02:
- The 0 before the decimal point is a leading zero.
- The zero after the decimal point and before the 2 is also a leading zero.
- The digit 2 is a nonzero digit and therefore significant.
All the zeros in 0.02 are only used to place the decimal point; they do not indicate precision. They are leading zeros. Only the digit 2 carries precision.
Hence, 0.02 has 1 significant digit.
Why it matters:
Understanding significant digits is important in science and mathematics because they reflect the accuracy of a measurement or a calculated value. When reporting values in experiments or calculations, using the correct number of significant digits shows how confident you are in the value.
For example, if a scale reads 0.020 g, that is more precise than 0.02 g, because the first has 2 significant digits and the second has only 1. Even though the numeric value seems close, the confidence and detail in measurement are different.
So, for 0.02, there is only 1 significant digit, which is 2.
