This topic has been already covered in this forum a few times and most of the time the answer was that "for decimals plural of the unit is used", e.g. 0.5 meters (not 0.5 meter). However, the National Physical Laboratory (NPL), which is the UK's National Measurement Institute, writes that: "For unit values more than 1 or less than -1 the plural of the unit is used and a singular unit is used for values between 1 and -1." The Federal Reserve Board, the central bank of the United States, also uses a singular unit for decimals "For the crude stage, the operating rate increased 0.5 percentage point, to 89.0 percent, a rate that was 2.5 percentage points above its average from 1972 to 2009." Therefore, could you please provide any evidence or link to some English grammar or style guide, which will clearly say that for decimals a plural unit shall be used?