Philippe Billot wrote:Hi Edwin,
Is it Guessing Someone's Age, page 166 ?
Gardner calls them Number Cards (page 95). He goes on to mention the more elaborate variant known as Window Cards, which are also described in Rouse Balls Mathematical Recreations and Essays. The latter has been through many editions since its first publication in 1892, but the window cards are definitely in the 10th edition of 1922.
Cyborg in the Dan Garrett lecture notes is a card location. You have the four 10s and deal more cards onto each one, counting back from ten to zero until the value of one of the dealt cards matches the number youve reached. Its similar to Twisting the Plot in The Classic Magic of Larry Jennings.