Ah yes, I spent too much time in my youth on this one. And then I had (er, still have) a book which included these.

Calculator Riddles

Q: What's white, round on top, flat on the bottom, cold on the outside, warm on the inside, and sometimes full of Eskimos?
A: 16 x 49 + 7 / 10000.

Q: What else is round and white, but looks like a zero?
A: 331 x 3 + .356009.

A Mid-Winter's Tale

Calculators usually don't say much, but every once in a while, they say one thing after another. For instance, one Christmas Eve, my calculator (whose name is 7 x 5 x 10 x 11 + 9 x 2) fell off the shelf and woke me up. It was obviously trying to tell me something. I hastily pressed 5 + 1 x 5 x 5 - 3 x 5 + 3 x 5 + 1 x 5 x 5 x 5 + 30000. I didn't exactly understand, but seeing that it wanted to say more, I did not press C but - 433637 instead. So that was it! And when I listened hard, I too could hear them. By then the calculator was wiggling again, so I pressed C and then .10001 + .00100 x 4. And sure enough, when I put my ear to the chimney I could hear it also. And I had forgotten to hang up my stocking! I rushed to the dresser to get one, but the drawer was empty. "Quick, where did I leave my stockings?" I asked, and feverishly pressed 102 x 104 + 1 x 5. And that's just where they were, right where I had left them. What a relief! I grabbed one and started running, but the calculator jumped a foot in the air. "What's the matter?" I asked, pressing 53704. The machine was right. The stocking was full of them. I took the other stocking instead, and hurried with it to the fireplace. We made it, but it was a close call.

- from Calculator Games by Michael Donner. Golden Press, 1977.

(Why don't I ever throw anything out? And can anyone else remember when a book could be purchased for $1.95?)