Paced Serial Addition test online: a visual PASAT

Digits from 1 to 9 appear one at a time, a new one every 1.8 seconds. Each time, you add the newest digit to the one before it and tap whether the two make less or more than 10. Your score is how many of the 60 pairs you get right.

Start Paced Serial Addition

60 paced pairs · about 4 min · touch, mouse or keys

When the last digit has gone you see your count out of 60 and can keep it with a free account.

3 5 9 8 14 < 10 > 10
5 + 9 = 14: more than 10Test pace · a digit every 1.8 s

How it works

3 short practice steps come first, from your own pace up to the test pace. Then one run of 60 digits, a little under 2 minutes. With the instructions it takes about 4 minutes.

  1. 1 · Before the test

    3 practice steps

    First at your own pace, with the sum shown after each answer. Then a digit every 2.3 seconds, then the test pace. If fewer than half are right at the test pace, that step runs once more. Practice is not scored.

  2. 2 · Every digit

    Add the last two

    Add the digit on screen to the one just before it, never to your previous answer. The two never make exactly 10, so every pair has one right side.

  3. 3 · Every digit

    A fixed beat

    Each digit shows for 0.6 seconds and the next arrives 1.8 seconds after it appeared. Your answer for a digit counts until the next one appears.

  4. 4 · Every digit

    Less or more than 10

    Tap one of 2 large buttons, or press the left arrow key for less and the right arrow key for more. The first press for each digit is the one that counts.

The test opens with one digit that has no answer: you keep it in mind, and the first answer comes with the second digit. During the test there is no feedback, only a brief highlight on the button you pressed, so the beat never stops for you.

The original task was spoken. Gronwall (1977) played digits from a tape at a fixed rate, asked people recovering from concussion to say each sum aloud, and followed how their scores came back over the weeks after the injury. This page follows a later visual adaptation built by TestMyBrain: digits on a screen, and a choice between 2 answers in place of saying the sum.

What it measures

Each digit asks for the same small loop under a clock you do not control: read the new digit, add the one you are holding, pick a side of 10, then drop the older digit and hold the new one.

Speed under load

  • Processing speed: how quickly you take in a digit and act on it while the next one is already on its way.
  • Working memory updating: holding one digit, then swapping it for the newest, again and again.
  • Single-digit addition, done fast enough that it barely registers.

Attention over time

  • Sustained attention: 60 digits in a row with no pause to regroup.
  • Recovering after a slip: picking up again at the next 2 digits instead of losing several.
  • Keeping the beat: answering inside the window on almost every digit.

Tombaugh (2006) reviewed decades of research on the spoken version. He describes it as a test of information processing speed and working memory that is sensitive to concussion, multiple sclerosis and other changes in how quickly the brain handles information. He also notes that many people find it unpleasant, which is part of why formats with easier answers were developed.

Fos and colleagues (2000) found that a visual paced version behaves much like the spoken one, so reading digits instead of hearing them keeps the core of the task. Arithmetic is the main caveat. People who find quick sums effortful start every digit a little behind, and scores on the spoken test are related to mathematical ability (Chronicle and MacGregor, 1998). A low count can reflect arithmetic fluency as much as speed, so it is best read next to the number tests.

A test, not a diagnosis.

A count from one 60-digit run describes that run. On its own it cannot confirm or rule out a diagnosis.

What you get

Your count appears as soon as the last digit has gone.

On the result screen

  • How many of the 60 pairs you got right, in large type.
  • A one-line reading against adults who took the same test on TestMyBrain: below, within or above the range most of them reach.
  • A bar from fewer to more right, with a shaded middle band and a marker for you.
  • A strip of 60 squares marking each digit right, wrong or missed, and your count for each third of the run.
  • A data panel with wrong answers, misses and response times, plus a CSV file of every digit.

When you keep it

  • Keep the count with a free account and reopen it on any device.
  • It sits under processing speed in your results, beside Symbol Coding and Reaction Time once you take them.
  • A report compares your count with adults in your own age band rather than with everyone at once.

How this version is scored

Every digit records the one before it, the sum, your answer and when you gave it. The score comes from the 60 test digits only.

Correct
The answer that matches the sum of the digit on screen and the one before it. Only the 60 test digits count; the practice steps do not.
Wrong
The other answer. A wrong answer and a missed digit both count against accuracy, which is how TestMyBrain scores the test.
Missed
No press before the next digit appears. It is recorded as a miss and counted as not right. A later press belongs to the next digit, never to the one that has gone.
Accuracy
Correct answers out of 60, as a percentage. This is the number the comparison uses.
Response time
The median time from a digit appearing to your press, over correct answers only, in milliseconds. It is shown for clinicians and does not change the score.

Same digits as the comparison sample. The 60 digits come in the same order as in the TestMyBrain version, at the same pace and after the same first digit. That is why your count can be set against theirs directly, without an approximate conversion.

Phones are fine. The score counts right answers, not milliseconds, and each digit leaves 1.8 seconds to answer. In the TestMyBrain data, average accuracy was close on iPhones (73%), iPads (74%) and Mac computers (77%).

A fixed order. Because the sequence never changes, a second attempt is a little more familiar. TestMyBrain found almost no practice effect (74.8% on a first attempt, 76.0% on a repeat), but keep it in mind when you compare attempts.

Reference values

TestMyBrain published a normative sample of 1,000 adults aged 18 to 89 who took this test online. These are the counts it shows by age.

Correct answers out of 60 by age band, TestMyBrain Analysis Toolkit
AgePeopleMedianMiddle half
18 to 241304740 to 54
25 to 341844837 to 55
35 to 441854837 to 53
45 to 541764636 to 53
55 to 641624434 to 50
65 to 741074131 to 50
75 and over563228 to 44

Middle half: from the 25th to the 75th percentile of each band, rounded to whole answers.

The sample was drawn evenly across ages, so the oldest band is the smallest: 56 people aged 75 and over. Its edges rest on few people.

Your report compares your count with your own age band in this table. The result screen uses all ages together.

Before you start

The score is a count of right answers at a fixed pace, so anything that slows a sum or breaks your focus shows up in it.

For a cleaner attempt

  • Pick a quiet moment: 2 minutes without a notification or a question from someone nearby.
  • Hold a phone steady or rest it on a table, so both buttons stay under your thumbs.
  • Use the practice steps to settle into the rhythm, not to race.
  • If you lose the thread, let one digit go and start again with the next 2.

Interpret cautiously when

  • Quick single-digit sums take you real effort, for example if arithmetic has always been hard; the number tests help read the result.
  • You were tired, anxious or unwell, or were interrupted during the 60 digits.
  • You have low vision or use assistive input that makes a 0.6-second digit or a quick tap hard.
  • You have done this test before and remember parts of the sequence.

Questions

What does the paced serial addition test measure?

Mainly how quickly you can process new information while updating what you hold in mind, at a pace set for you. Each digit needs a quick sum, a choice and a switch to the newest digit, so working memory and sustained attention matter as much as raw speed. Single-digit arithmetic is part of every answer too.

Why does the paced addition test feel so stressful?

Because the pace never waits. Most people miss some digits and notice each miss, and that pressure is part of how the task works. Tombaugh (2006) notes that many people find the spoken original unpleasant. Feeling pressed is normal and does not mean you did badly; your count is compared with people who felt the same pressure.

What if I lose the thread?

Let one digit go and start again with the next 2 you see. A missed digit costs one answer, while trying to catch up on old sums tends to cost several. The result screen shows where in the run your misses fell, so a short lapse is easy to spot.

Can I take the paced addition test on my phone?

Yes. The 2 answer buttons are large, the score counts right answers rather than milliseconds, and each digit leaves 1.8 seconds to answer, so touch timing on a phone does not change the result in any meaningful way. Use the same device if you want to compare attempts.

Is this the same as the PASAT?

It is a close relative. The PASAT reads digits aloud and asks you to say each sum. This visual version shows the digits and asks only whether each sum is less or more than 10, which keeps the pace and the updating but makes answering simpler. Its comparison sample took the same visual version.

Sources

By Cristian Dominguez Rein-Loring, Creative Technology Lead · Updated October 12, 2026