Short-term memory: digit spans, chunking and online tests

Remembering a short number sequence depends on how it is presented and how you group it. A digit-span test measures one particular task, rather than memory as a whole.

Sequence recall asks you to reproduce an order; the covered-number task asks you to remember positions. Compare attempts within the same task. Neither score converts directly into IQ or a fixed number of memory slots.

Repeat the flashing sequence and see how many steps you recall. Click the remembered number positions after they are covered.

Since the hardware (working memory capacity) is hard to change, we can optimize performance by upgrading the software algorithm. The most effective method is "Chunking."

Remember the "chunks" from Miller's Law? 194919902026 is 12 digits, hard to remember. But if you break it down into 1949 (founding), 1990 (birth), 2026 (now), it becomes 3 chunks of information.

For the brain, remembering 3 chunks is a breeze. This is the secret of memory masters who memorize a deck of cards in minutes—they aren't remembering 52 cards, but 52 vivid story scenes.