The fours be with you! ... and double cream, half sugar, please

Here's the number word game called The Four's Be With You, from Prof. Bob Marks's presentation on things computers will never do:

Spell a number. (Say, t-w-o.)

Count the letters. (3)

Spell that number. (t-h-r-e-e)

Count the letters of that number. (5)

Count the letters of that number. (f-i-v-e = 4)

Prof. Marks says, you will always end at four/4 letters.

Huh? I tried it a few more times:

Twenty 6
six 3
three 5
five 4

thirty-six 8 [I suppose I should not count hyphens]
eight 5
five 4

Okay, I am trying this one more time. I have work to do:

one hundred thirty eight [I suppose I should leave out the "and"] 21
twenty one 9
nine 4

This seems like a good icebreaker, while we wait for late arrivals at a meeting. But you have to wonder about people who figure this kind of stuff out. Like what weren't they doing? (Stocking the shelves? Mending fence? Answering the phone at the Complaints desk? Might explain a lot ... )