Knuth points out a very useful property of the Fibonacci number base: conversions between kilometers and miles.
All you do is shift the digits!
For example, say I want to convert 65
kmh to
mph. Well, 65
10 = 55 + 8 + 2 = 100010010
fib, and shifting (
right) we have 10001001
fibmph = (34 + 5 + 1)mph = 40
10mph (it's actually closer to 41
10mph).
Details of why this works are left as an exercise to the interested reader.