There have been a few discussions on this (an example: 0.175 meters, or 0.175 meter? ). It is because we use units (like seconds, metre hectares etc) in the plural for any quantity of the items being measured. (The only exception is when there is only, and exactly, one of them).
One metre, 0.9 metres. 1.1 metres
One second, 0.5 seconds. 1.5 seconds