Question

You need to measure a nail in centimeters, but you only have a standard ruler. The nail measures one inch long. About how many centimeters is this? 0.25, 2.5, 25, 250.

Answer 1

1 inch is about 2.5 centimeters

Answer 2

An inch is 2.54 centimeters, so obviously if you round 2.54, the finger nail is 2.5 centimeters.