Convert rod to hectometer

The in-between metric units are taught at school and then mostly forgotten – except regionally. Dutch motorways carry a 'hectometre post' every 100 m, so traffic news and breakdown services place a jam at 'A2, hectometre post 57.3'. In Sweden and Norway the decimetre is an everyday word, a half-decimetre being about two inches, and the decilitre does the same job in Nordic recipes. The decametre is the odd one out: 10 m is about the length of a bus, and the unit is hardly used anywhere.

Gunter's chain of 1620 tied land measure to the acre: a chain is 66 ft or 100 links, 10 chains make a furlong (the length of a furrow), 8 furlongs a mile, and an acre is one chain by one furlong. Rods (16½ ft, a quarter chain) and chains still appear in US and Canadian deeds, and furlongs in horse racing. The US survey foot, 1200/3937 m, differs from the international foot by two parts per million, which adds up over a state; it was retired for new work on 1 January 2023, though survey data and legal descriptions in survey feet remain.