Mystery Computer Cards

(Vintage “Computer Age” Number Mystery) – New / Old Stock (1970s Hong Kong)

Step right up to the original “analog computer” miracle—a classic dime-store novelty that still fries brains today.

The Mystery Computer Cards (also known as Computer Age Cards or Number Mystery) lets a spectator secretly think of any number from 1 to 63, and you instantly reveal it with nothing more than a few printed cards and a quick bit of “mental arithmetic.” (Spoiler: the cards do the heavy lifting.)

Here’s the effect:
A spectator thinks of a number—no forcing, no fishing, no questions that feel like a lie detector test. You show six special number cards and ask them to simply say which cards contain their number. In seconds, you add just a few values and announce their exact number. It feels like mind reading… powered by a tiny, charming slice of vintage math.

What makes this a winner is the method: it’s based on binary mathematics—the same “powers of two” logic computers use (1, 2, 4, 8, 16, 32). Each card’s top-left number is one of those values. Add the top-left numbers from the cards the spectator named… and the total is always their thought-of number. Clean, direct, and surprisingly fooling—especially because it looks like a quirky retro toy.

Why you’ll love it

• Beginner-friendly: no sleight-of-hand required
• Fast reset: ready to go again immediately
• Plays big: great for walk-around, kids shows, classroom demos, and “math magic” moments
• Vintage charm: 1970s Hong Kong dime-store novelty style—fun to perform and fun to collect

Condition

• New Old Stock – never opened
• Vintage item from the 1970s (packaging may show age/storage wear, but contents are unused)

If you like magic that’s smart, simple, and oddly addictive, this little “mystery computer” belongs in your pocket.