“When I was a boy,” said Michael Stifel, “we had a couplet which ran like this:
Ten fingers have I on each hand
Five and twenty on hands and feet.
You know we used to say 'five and twenty' for twenty-five. The statement is perfectly true, but how do you explain it?”
At this the company lapsed into silence for a time.
“But I don't have 'five and twenty' fingers on my hands and feet,” insisted Wu.
“You must think of your toes as fingers,” said Robert.
„It is easy enough if you only know how,“ said Michael.
Then Heron said, “The explanation is—”
“Don't give it!” called out several voices. “We want to think it out for ourselves.”
And so I shall have to leave it for you.
“Can any of you write an even number, using only odd digits?” asked Adriaen.
“I can,” said Cuthbert. “It is just as easy as writing a hundred without using zero.”
“Well, don't tell us,” said Gupta. “We also want to think this out for ourselves.”
