Digit Span

What you see

Each trial is one sequence. The screen has three parts, one above the other: the sequence row, the recall row and the keypad, under a one-line prompt.

• The prompt. While the sequence is shown, the line under the prompt names the recall order, for example "Recall order: backward, last symbol first." On levels where the order is drawn at random, it says instead that "the recall order is shown when the sequence ends", and the order appears in the prompt only once recall opens. The number of slots in each row tells you how many symbols are coming.
• The sequence row. After a half-second pause, the first slot lights and shows its symbol. Each symbol stays up for the level's display time, then the next slot takes over, with no blank between them. Slots already shown go dim, so you can always see how far through the sequence you are, but never the symbols themselves.
• The delay. On some levels the last symbol is followed by a silent retention gap of one to three seconds before you can answer.
• The recall row and keypad. When recall opens, the keypad lights up. Click symbols or type them on your keyboard; they fill the recall row from left to right. Backspace, or the Delete key under the keypad, removes the last entry. The row stops accepting input once it is full, so you can never enter more items than were shown. There is no clock on the recall phase, and time is not part of the score. Press Check answer when you are done. After the check the whole sequence is shown, each recall slot turns green or red, and if your answer was not exact the correct recall appears underneath.

The three recall orders

• Forward: the order they appeared.
• Backward: last symbol first.
• Ascending: lowest to highest. When letters are mixed in, all digits come first (0 to 9), then letters alphabetically. If a symbol appeared twice, it appears twice in your answer.

The ten levels

Practice sessions start at level 3. A Correct answer moves you up one level; a Partly correct answer keeps you where you are; an answer with nothing right moves you down one.

How sequences are built

Sequences are random but filtered so that easy patterns cannot do the work for you:

• No symbol twice in a row. You will never see 4 4.
• No runs of three in a row, up or down. Sequences like 4 5 6 or 9 8 7 are rejected. Letters continue the count after 9, so 9 A B is rejected too.
• Repeats are rationed. On levels 1 to 7, at most one symbol may appear twice (never back to back). From level 8 no symbol repeats.
• No I or O. Letter sequences use A to Z without I and O, so a round symbol is always the digit zero.
• The keypad never helps. It shows the full set, all ten digits or all 34 symbols on mixed levels, not just the ones in your sequence.

Try the level 2 pace yourself. Hold the five digits, then reveal them to check.

Ordering exerciseSign in to try it

What it measures

Digit span has been part of the Wechsler intelligence scales since their first edition. The fourth edition of the adult scale (WAIS-IV) runs it in three conditions, forward, backward and sequencing (ascending order), which are exactly our three recall orders. Researchers commonly treat forward span as a measure of verbal short-term memory and attention, and backward and sequencing as working memory, because they require you to manipulate what you hold. In a study of 246 older adults, backward digit span was more difficult than forward, while the spatial Corsi block test was not, which the authors took as a sign that backward digit recall leans more on the central executive.

In Baddeley's model, forward digit span sits mostly in the phonological loop: you hear the digits in your inner voice and keep them alive by rehearsal. Backward and ascending recall add work for the central executive, which must reorder the list without losing it. The retention gap tests whether rehearsal can hold the list over a delay, and letters mixed with digits remove the comfort of a single familiar category.

In our taxonomy, Digit Span feeds the span capacity facet of memory and carries the largest weight of any game in the memory score. Its competency tags are 75% working memory and 25% associative memory.

How it is scored here

Every answer is compared with the expected answer for that recall order and scored out of 10,000 points by edit distance: the smallest number of single changes that turn your answer into the right one. The changes counted are inserting a missing symbol, deleting an extra one, replacing a wrong one, and swapping two neighbours. Each costs one edit.

Your trial score is 1 − (edits ÷ sequence length), and never below zero. So on a five-symbol sequence, each edit costs 2,000 points.

What follows from the rule:

• Only an exact answer is "Correct" and only a Correct answer moves you up a level.
• Anything with at least one thing right is "Partly correct" and holds your level. Most misses fall here, so one slip does not send you down.
• An answer with nothing right is "incorrect" and moves you down one level.
• A wrong guess costs the same as a gap. Leaving a symbol out and typing a wrong one are both one edit, and a right guess costs nothing. When you are unsure of a symbol, enter your best guess rather than leaving the slot empty.
• Swapping neighbours is cheap; scrambling is not. A swap of two adjacent symbols is one edit. Mixing up symbols further apart costs two or more.

From trials to your 0–100 score

Time does not count at all in Digit Span: rushing recall earns nothing. Each trial's score is weighted by how hard the trial was, measured from the sequence itself: its length, plus extra weight for faster display (anything quicker than 1.2 s per symbol) and for a longer delay before recall. The recall order is not part of that weight; its difficulty shows up in how often you get the trial right. On our 0–100 scale, 50 means you scored what the difficulty you work at predicts. You need about four trials before a score appears, and a small number of trials is pulled toward 50 until the evidence builds.

Your session report also shows four measures from your trials:

Note that "positions recalled correctly" is stricter than the trial score. If you forget the third of five symbols and type the rest, the trial loses one edit (8,000 points), but every symbol after the gap has shifted left, so only two of the five positions count as right.

Where you will meet it

• pymetrics (Harver). Preparation sites describe its Digits game as a forward digit span that starts at four digits, lengthens by one after each correct answer, shortens by one after each mistake and ends after three mistakes. Our levels 1 to 3 are the same task.
• Clinical and psychometric batteries. The Wechsler scales' digit span, with forward, backward and sequencing conditions, is the direct ancestor of our three recall orders.
• Other span games. Tile and grid sequence games, such as the sequence task that preparation sites describe in Arctic Shores' battery, are the spatial version of the same idea. The ordered-recall habits you build here carry over; practise the spatial side with GridRecall.

The method

1. Read the recall order before the first symbol

   Read the line under the prompt. If it says the order will be revealed at the end (levels 7, 8 and 10), plan to store the sequence exactly as it arrives and transform it only once you know the order.

2. Group as the symbols arrive

   Do not try to hold loose items. Bundle them in threes as they come: 4 symbols as 2 + 2, 5 as 3 + 2, 6 as 3 + 3, 7 as 3 + 3 + 1. Hear each group as one rhythmic unit, like part of a phone number: "six-one-eight, three-nine". This is the recoding Miller described: fewer, bigger units.

3. Keep letters as sounds

   On mixed levels, say letters by their names inside the groups: "seven-K-two, D-nine-B". Do not try to sort while symbols are still arriving unless the order is already known to be ascending; sorting and listening compete for the same inner voice.

4. Rehearse through the delay

   During the blank delay (up to three seconds at level 9), cycle your groups silently, once or twice. Do not look away or start guessing at the keypad layout.

5. Transform in chunks, then enter

   Backward: reverse the order of the groups, then reverse inside each group. Ascending: pull out the digits low to high, then letters A to Z. Count your answer against the number of slots before you check.

6. Fill every slot

   If one symbol is gone, type your best guess in its place. A wrong guess costs no more than a gap, and a right one costs nothing.

Worked example 1: backward, level 5

Five digits at 800 ms, recall backward. Watch it, then work out the answer before you open the solution.

Ordering exerciseSign in to try it

Show the solution

Chunks as heard: 836 and 15. Swap the chunks: 15, then 836. Flip inside each: 51 and 638. Answer: 5 1 6 3 8. Check: the last digit shown (5) comes first, the first digit shown (8) comes last. Five symbols, matching the five slots.

Worked example 2: ascending, mixed, level 9

Six symbols at 700 ms, three seconds of silence, recall ascending. The sequence is 7 K 2 D 9 B.

Show the solution

Encode as two groups: "seven-K-two, D-nine-B". Because the order is known to be ascending, you can split as you go: digits 7, 2, 9 and letters K, D, B. During the three-second delay, rehearse both sets once already sorted: "two-seven-nine", "B-D-K". Answer: 2 7 9 B D K. A common mistake is to place B straight after 2 because it "looks small". All digits come before any letter.

Worked example 3: order revealed at recall, level 7

Five digits, 4 9 2 6 1, then a one-second delay. The recall order is only confirmed when the sequence ends.

Show the solution for each possible order

Store it forwards as 492, 61. Then transform when the order appears:

• Forward: 4 9 2 6 1.
• Backward: swap the chunks (61, 492), flip inside: 1 6 2 9 4.
• Ascending: 1 2 4 6 9.

Storing forwards costs nothing if the order turns out to be forward, and every other order is one transformation away. Trying to prepare two orders at once while the digits are still arriving is how people lose the fourth and fifth digits.

Tips and traps

Levelling up

Starting at level 3, the first jumps change the kind of task more than its length:

• Level 4 switches to backward recall and drops the length to four. Reverse chunk by chunk rather than item by item.
• Level 6 introduces ascending order. Anchor the smallest and largest digits as they appear, then place the middle.
• Level 7 makes the order unpredictable. The store-forwards habit from worked example 3 becomes essential.
• Level 8 adds letters. Keep them as sounds.
• Level 9 is ascending with six mixed symbols at 700 ms and a three-second delay: the longest wait in the game. Sort during the delay.
• Level 10 is seven mixed symbols in a random order at 700 ms. Three groups (3 + 3 + 1) and a clean transformation are the only reliable approach.

1. Week 1
   • Three sessions of 5 to 10 minutes
   • Group every sequence into threes, even the easy ones
   • After each session, check your error type: order slips or lost items
2. Week 2
   • Aim to hold level 5 (backward)
   • Drill chunk-swap-flip until it feels automatic
   • Try the practice sequences in this lesson at their own pace
3. Week 3
   • Push into levels 7 to 9
   • Store forwards on every revealed-at-recall trial
   • Mix in one Flashback and one GridRecall block per session

Check yourself

5 practice questions

1. The expected forward answer is 6 1 8 3 9. You type 6 8 1 3 9. What happens?
2. Level 9, ascending. The sequence is 7 K 2 D 9 B. What is the answer?
3. You are sure of four of five symbols but the third is gone. What should you enter?

and 2 more

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Sources

1. Egeland, J., Lund, O., and Raudeberg, R. (2025). Measuring working memory span with WAIS-IV: digit sequence is the superior span test. Applied Neuropsychology: Adult, 33(1), 65–72. doi:10.1080/23279095.2024.2330998
2. Pacho-Hernández, J. C., et al. (2025). Neurocognitive performance and executive functions do not influence conditioned pain modulation in women with migraine. Life, 16, 27 (describes the three WAIS-IV digit span conditions). doi:10.3390/life16010027
3. Kessels, R. P. C., van den Berg, E., Ruis, C., and Brands, A. M. A. (2008). The backward span of the Corsi Block-Tapping Task and its association with the WAIS-III Digit Span. Assessment, 15(4), 426–434. doi:10.1177/1073191108315611
4. Baddeley, A. (2012). Working memory: theories, models, and controversies. Annual Review of Psychology, 63, 1–29. doi:10.1146/annurev-psych-120710-100422
5. Miller, G. A. (1956). The magical number seven, plus or minus two. Psychological Review, 63(2), 81–97. Full text
6. Murdock, B. B. (1962). The serial position effect of free recall. Journal of Experimental Psychology, 64(5), 482–488. doi:10.1037/h0045106
7. Grueso, S., Sánchez-Benavides, G., Santos-Santos, M., et al. (2026). Bilingualism and cognition: the impact of age of acquisition, language use, and proficiency in cognitively unimpaired older adults. Journal of Alzheimer's Disease, 113(1), 424–440 (classifies forward span as short-term memory and attention, backward and sequencing as working memory). doi:10.1177/13872877261469525
8. JobTestPrep. The pymetrics Digits game (candidate-reported mechanics). jobtestprep.com
9. JobTestPrep. Arctic Shores assessment guide (candidate-reported mechanics). jobtestprep.co.uk

Put it into practice: Digit SpanSign in to try it