Understanding significant figures is crucial in scientific measurements, as they convey the precision of a value. When determining the number of significant figures in a given value, the presence of a decimal point plays a key role. If the value includes a decimal point, you begin counting significant figures from the left, starting with the first non-zero digit. For instance, in the value where the first non-zero digit is 3, you would count all digits from that point to the end, resulting in a total of four significant figures.

To summarize the rules for counting significant figures:

• If a number has a decimal point, count from left to right, starting with the first non-zero digit.
• If a number does not have a decimal point, count from right to left, again starting with the first non-zero digit.
• Exact numbers, such as those derived from counting or defined quantities, are considered to have an infinite number of significant figures.

By applying these rules, you can accurately determine the number of significant figures in various measurements, enhancing the reliability of your scientific calculations.