Which unit would be best for measuring a small object such as an insect?

• A. Millimeters
• B. Centimeters
• C. Meters
• D. Kilometers

Answer: (A)

Measuring a small object requires a unit that is small enough to capture its tiny size. For something like an insect, millimeters fit that need because many insects are only a few millimeters long. Centimeters would be too coarse to show small differences, and meters or kilometers are far too large for such small measurements. Rulers often have clear millimeter markings, and the basic conversions help: 1 centimeter equals 10 millimeters, 1 meter equals 1000 millimeters. So using millimeters gives you the precision needed to measure a small object accurately.