- A furlong is 201 meters or 220 yards. It is derived from the length of a plowed furrow in an acre of farm field.
- A firkin is 40 kg or 90 lbs and is based on the weight of a quarter cask of ale.
- A fortnight is unit of 2 weeks, or 14 days. Here at Excel Math we get paid every fortnight, and tonight is the night!
This is a British sportscar known as the Jensen FF
(but as far as I know, Jensen did not use the FFF system)
From an elementary math point of view, FFF can be used for problems that force students to focus on doing things the mathematically-correct way. The very novelty of the units makes it difficult to take short-cuts or cheat.
For example, our common measure of speed is miles per hour or km per hour. A person can walk at a pace of 3 or 4 miles per hour. In cars we are usually driving at 30, 45 or 60 mph.
In the FFF system, 1 furlong per fortnight (FpF) is the speed of a snail who has almost fallen asleep, or a very, very slow bug.
Could we convert FpF to miles per hour? Sure. How?
We can start by learning the value of the equivalent units, like this:
- Hours in a fortnight = 14 days x 24 hrs/day = 336 hours/fortnight
- Furlongs per mile = 5280 feet ÷ (220 yards x 3 feet per yard) = 8 furlongs/mile
- 1 mile per hour is the same as 8 furlongs per 1/336th of a fortnight
- 1 furlong per fortnight is 1/8 mile in 336 hours = .125 ÷ 336 = .000372 miles per hour
- .000372 x (5280 x 12) = 23.6 inches in an hour
- 200 inches in a minute = 12000 inches in an hour
- 12000 ÷ 23.6 = 508 FpF
Teachers often say, "Now that you have learned this word or concept, can you use it in a sentence?" Okay, I will give it a try. Here is the context:
Because there is a nice micro-brewery by our Excel Math editorial offices, after work I may walk across the street and have a pint of beer.
Now putting it in FFF units:
After I pick up my fortnightly paycheck (.015 fortnights from now), I will walk .5 furlongs and drink 1/72nd of a firkin.
PS - Lightning Brewery - where their methods are scientific, but their goals are artistic - does NOT employ the FFF system of measures.