how many significant figures are in this length? 0.002500 dm

Explanation:

Step1: Identify significant - figure rules

Non - zero digits are always significant. Leading zeros (zeros before non - zero digits) are not significant. Trailing zeros (zeros after non - zero digits) are significant if there is a decimal point.

Step2: Analyze the given number

In 0.002500, the non - zero digits 2 and 5 are significant. The two trailing zeros after 5 are also significant because of the decimal point. The leading zeros (the three zeros before 2) are not significant.

Answer:

4