Final answer:
To express 0.36 to three significant figures, we write it as 0.360, where the last zero is the third significant figure without altering the value of the original number.
Step-by-step explanation:
To convert the number 0.36 to three significant figures, we need to look at the digits from left to right, identifying the first non-zero digit as the first significant figure.
Since 0.36 already contains two non-zero digits, it already has two significant figures. To express it with three significant figures and since there's no digit to add, it remains as 0.360 with the last zero counting as the third significant figure.
When dealing with significant figures, we must ensure that we do not change the value of the number by adding or subtracting anything substantial. Adding a trailing zero does not change the value of the decimal but does increase the number of significant figures to the required amount.