Memory
Backward Digit Span
A number appears, then vanishes. Type the digits in reverse order. 3-8-2 becomes 2-8-3. The string grows until you miss. Backward span is harder than the forward Number Memory test because you must hold the list and flip it.
Played 8,303 times · average 5 digits
A number appears, then vanishes. Type the digits in reverse order. 382 becomes 283.
Pick a length
Short is a quick check. Long is the full run. Your best for each is stored on this device.
What this measures
Backward digit span is a working-memory staple. Forward span can ride a sound loop. Backward span forces manipulation: you store the list, then reorder it. That extra step is why typical backward scores sit one or two digits below forward scores. Clinicians use both directions to separate simple storage from working memory. We keep the same grow-until-miss rule as Number Memory so you can compare the two pages on the same day.
Where this shows up in real life
Repeating a booking code backward is a party trick. The useful skill is holding a list while you reorder it, the same buffer you use to reverse a route in your head.
How to improve
- Chunk in pairs from the end: if you saw 58291, start building 19, then 28.
- Say the forward list once, then recite it backward before the box appears.
- Do not type the first reverse digit until the whole reverse string is ready.
- Compare with Number Memory the same hour. The gap is the working-memory tax.
Frequently asked questions
What is a good backward span?
Five reverse digits is typical. Seven is strong. If your forward span is 8 and backward is 4, the flip is the weak step, not storage.
Why is reverse harder than forward?
Forward can be a tape you replay. Reverse needs you to walk the tape backward, which uses the same buffer you need to store the unused digits.
Does chunking count as cheating?
No. Chunking is how digit span grows in real life. Phone numbers exist because of it.