Serial Addition
Keep a running total in your head
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What is the Serial Addition?
Serial addition means adding each new number to a total you hold in your head. It is the basis of the Paced Auditory Serial Addition Test, or PASAT, developed by Dorothy Gronwall in 1977. In the PASAT, single-digit numbers are read aloud at a fixed pace and the listener adds each number to the one that came just before it, saying each sum out loud.
Researchers and clinicians use the PASAT to assess working-memory updating and information-processing speed, because the task gives no time to rehearse and the pace does not wait for you. The Neuroptimize Serial Addition game borrows the paced, one-at-a-time format but asks you to keep a single running total, with subtraction, multiplication and division joining as your level rises.
How to play the Serial Addition
- Each round starts with a number on a card. Remember it, then watch as operations such as + 7 or − 3 appear one at a time.
- Apply each step to your running total in your head. Each card stays visible for a fixed time: about 1.8 seconds at level 1, getting shorter until it is under a second at level 30.
- When the last step disappears, type the final total on the keypad and tap the tick to submit it. You can also use the number keys and Enter on a keyboard.
- A wrong total counts as a mistake. After every answer, the full chain is shown with the running total under each step, so you can see where you went wrong.
- A session has 8 rounds at low levels, 7 from level 12 and 6 from level 22. Within a session, each correct answer adds a step to the next chain and each mistake removes one.
- The base chain length rises from 2 steps at level 1 to 7 at the top levels. Subtraction joins from level 3, multiplication from level 8 and division from level 14, and the numbers get bigger as you climb.
Strategies and tips
Update, then let go
As soon as you have applied a step, replace the old total with the new one and forget the step. Holding only one number keeps your working memory clear for the next card. Trying to remember the whole chain usually makes things harder.
Say the total silently
Quietly repeating the current total in your head helps keep it active while you wait for the next card. Saying "thirty-four" after + 9 and "thirty" after − 4 gives you a steady rhythm.
Add through the next ten
For 47 + 8, add 3 to reach 50, then add the remaining 5 to get 55. Bridging through a round number is quick and reliable when cards are shown for under a second.
Use the full card time
Each card stays on screen for a fixed time, and there is a short gap before the next one. Finish your calculation during that window rather than waiting for the next card to appear.
Expect divisions to work out
The game only offers ÷ when the current total divides exactly. If you reach a division that does not come out evenly, your total has probably slipped. Use this as a cue to stay extra careful on the remaining steps.
The science behind the Serial Addition
Serial addition requires adding each new number to a running total held in mind. It is the basis of the Paced Auditory Serial Addition Test (PASAT), developed by Dorothy Gronwall in 1977, which is used to assess working-memory updating and information-processing speed.
Frequently asked questions
What is the PASAT?
The Paced Auditory Serial Addition Test is a test in which numbers are presented at a fixed pace and each one must be added to the number before it. It was developed by Dorothy Gronwall in 1977 and is used to assess working-memory updating and information-processing speed.
How is this game different from the PASAT?
The PASAT is spoken and asks you to add each number to the previous number only. In the Neuroptimize game, steps are shown on screen and you keep one running total through the whole chain, which can include subtraction, multiplication and division at higher levels.
Why do the chains get longer and shorter during a session?
The game adjusts the chain length after each round. A correct answer adds one step to the next chain, and a mistake removes one, within a small range around the base length for your level.
Is Serial Addition free?
Serial Addition is a Pro game in Neuroptimize, and Pro starts with a 7-day free trial. Free players can also get it as the Pro game of the day in their daily workout.