1 # Three digits in, 2/6 digits out, rounding down.
12 # One digit in. Must not produce spurious digits or trailing nulls.
25 # Three digits in, 2/6 digits out, rounding up.
35 # Three digits in, 1/6 digits out, rounding down.
47 # One digit in. Must not produce trailing nulls.
60 # Three digits in, 1/6 digits out, rounding up.