Answer:
0.259
Explanation:
There are some rules in determining what numbers are significant figures.
- All non-zero numbers are significant.
- Zeroes between two non-zero numbers are significant.
- Zeroes at the front of a number are not significant.
- Trailing zeroes are only significant if there is a decimal point.
We can determine how many significant figures the number currently has.
- The first zero is not significant.
- 2, 5, 9, and 1 are significant because they are non-zero numbers.
- The zero between 9 and 1 is significant because it is a captive zero.
- The zeroes at the end of the number are significant because they are trailing zeroes.
There are currently seven significant figures. In order to round the number to three significant figures, we must round it to the thousandths place, or the 9.
The rounding rules are:
- If the digit in the place after the number we are rounding is less than 5, you round down (or in other words, keep the number the same; Ex: 74 becomes 70)
- If that digit is greater than 5, you round up (Ex: 78 becomes 80)
Since 0 is less than 5, the number rounded to 3 significant figures is 0.259.