Memory tasks

Working memory test: hold letters through the arithmetic

Remember letters while solving short arithmetic problems, then recall them in order.

18 letters, as many statements
2 min
Free, no sign-up

For the fairest comparison, retake on the same device.

Results on screen · no email

About this test

Keep letters in mind while judging arithmetic statements. Four sets contain 3, 4, 5 and 6 letters. Results show letters recalled in position and statements answered correctly. No published norm fits this page's four sets of letters, so its result has no typical figure. For context, research on working memory puts its central capacity in young adults at about 3 to 5 meaningful items at once (Cowan, 2010), and adults repeat about 4.6 digits in reverse order against about 6.4 in the order heard (Woods and colleagues, 2011).

How the task works

A statement such as 6 × 3 − 2 = 16 appears; answer True or False with the buttons or the T and F keys.
A letter follows for under a second. Hold it, then answer the next statement.
At the end of each set, give the letters back in the order they appeared, using the letter pad or your keyboard.
Four sets run: three letters, then four, five and six. Every set runs whatever happened in the one before, so there is no ladder to fall off.
The arithmetic is not filler — it is what stops the letters being rehearsed. Judge fewer than 85% of the statements correctly and no recall figure is printed.

Task accessibility

Time: 2 minutes
Length: 18 letters, as many statements
Result: your times and counts

Your answers stay in this browser tab. If you sign in, you can save your result (not your answers). When session replay is on, it can include visible questions, choices and results. Privacy details.

For context

What related span tasks typically find

There is no published norm for this page's exact task, so these are the figures research reports for related measures. They are context, not a score to compare yours with.

Means and ranges from Woods and colleagues (2011, 763 adults aged 18–65) and the summary in Cowan (2010).
Measure	Typical adult figure	Source
Digits repeated in the order heard	6.35 digits on average	Woods et al. (2011)
Digits repeated in reverse order	4.61 digits on average	Woods et al. (2011)
Items held at once in working memory	about 3 to 5	Cowan (2010)

An operation span asks you to keep letters in mind while judging sums, so it shows how much you hold while doing something else. Compare your letters-in-position count with your own earlier runs.

Where these figures come from

Cowan (2010) summarises evidence that working memory in young adults has a central store limited to about 3 to 5 meaningful items. Checked 3 November 2026
Woods and colleagues (2011) found that 763 adults aged 18 to 65 repeated a mean of 4.61 digits in reverse order, against 6.35 in the order heard. Checked 3 November 2026

Use the result

What this test adds

Arithmetic judgments fill the intervals between letters, so the task measures recall while another task is active. Low arithmetic accuracy prevents a recall figure.

A small next step

Run it again and try saying each letter once as it appears before you answer the statement; if the letters in position move, what changed was your strategy.

Questions people ask

What is the difference between working memory and short-term memory?

Short-term memory holds information briefly; working memory holds it and does something with it at the same time. Keeping four letters while you work out whether 6 × 3 − 2 = 16 needs both, which is why this route puts a statement between every pair of letters.

How is this different from the other memory tests here?

The digit span test next door is holding alone: digits in, digits back, nothing in between. This is the only route on the site that puts a second task between the items you have to keep, and the short-term memory test is the only one that puts a filled gap after them — three questions about memory, one each.

How is an operation span scored?

Each letter recalled in its original position earns partial credit across the four sets. The result also shows your arithmetic accuracy.

Why was my recall figure not printed?

Because fewer than 85% of the statements were judged correctly, which is what letting the arithmetic go in order to keep the letters looks like. That turns the task back into a plain list to rehearse, and the figure it would produce is a short-term span wearing a working-memory label, so the page prints none.

Is a short span a problem, and is a phone a fair device?

One run reflects this sitting. A phone works with the large letter pad; compare practice runs on the same device and input method.

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