Press the button to start
| Watch | The digits appear for a few seconds. |
| Type | Enter the sequence back in the same order. |
| Start | Begin from the shortest sequence. |
Number Memory shows you a string of digits for a few seconds, then asks you to type it back. Get it right and the next one is a digit longer. It is the classic digit span test used in psychology for over a century, and it puts a hard number on how much your short-term memory can actually hold.
The famous figure is seven plus or minus two, meaning most people manage between five and nine digits. What is interesting is how quickly that limit moves with technique: chunking the digits into pairs or triples can push a five-digit memory to eleven or twelve without any change in raw ability.
Chunk the digits into groups. Instead of remembering nine separate numbers, break them into threes and remember three groups, exactly as you would with a phone number. This one technique typically adds several digits to anyone's score.
Say the digits to yourself as they appear. Rehearsing them as sound keeps them alive in your working memory, which decays in seconds without repetition. Silent reading alone is much weaker than subvocalising.
Look for patterns and meaning. If part of the sequence forms a year, an age or a repeated pair, latch onto that. Meaningful chunks take up far less memory space than arbitrary digits.
Do not panic when the string gets long. Stress alone measurably shortens working memory, so staying calm and rehearsing steadily carries you a level or two further than tensing up and trying to force it.
Most people fall between five and nine. Getting beyond that usually means you are chunking effectively.
Grouping digits into small clusters, like reading a phone number in threes. It is the single most effective technique for this test.
Yes. Digit span has been used to measure short-term memory capacity for well over a century.
Your raw capacity changes little, but technique makes a large difference, so scores improve quickly with practice.
Nothing at all. The whole of Number Memory is built into the page itself, which is why there is no loading bar and no waiting before you can play.