Which equation correctly converts 3.25 inches to millimeters?

To convert inches to millimeters, it's essential to use the correct conversion factor between these two units. The conversion factor between inches and millimeters is that 1 inch is equal to 25.4 millimeters. Therefore, to find the equivalent length in millimeters for a measurement in inches, you multiply the number of inches by 25.4.

In this case, when converting 3.25 inches to millimeters, multiplying by 25.4 provides the accurate calculation:

3.25 inches × 25.4 mm/inch = 82.55 mm.

This demonstrates why the answer is appropriate for this conversion task. The other choices either involve incorrect operations or do not utilize the correct conversion factor needed to convert from inches to millimeters.