What's Your IQ

Counting
Span

Count the blue circles on each card in your head, ignoring blue squares and orange circles, then move on. Keep every count in mind: at the end of the set, enter all of them in order. Counting and remembering at once is what makes it hard.

Difficulty

Count theseIgnoreIgnore

SIMPLE VS COMPLEX SPAN

Remembering is easy. Remembering while working is not.

A simple span (like Digit Span) only asks you to store. A complex span makes you do something else between items, so you have to protect your memory while your attention is busy. Pick a task to see what fills your mind at each step.

STEP 1STEP 2STEP 3STEP 4STEP 5STEP 6

Processing

countcountcountcount–

In memory

55 · 75 · 7 · 45 · 7 · 4 · 6→ recall

Counting each card eats the attention you'd use to rehearse. Spans of 3–5 are typical for adults, even though each item is a single digit.

THE RESEARCH

A test built to study how children's minds grow

Robbie Case and colleagues introduced counting span in 1982. They found children's span grows steadily with age, and argued the reason is speed: as counting becomes automatic, it uses less mental space, leaving more room for memory. Counting span scores also predict reading and maths attainment in school.

Grows with age.Spans rise from about 2 or 3 at age six to 4 or 5 in adults.

Speed frees space.Children who count faster have larger spans, supporting Case's efficiency theory.

Predicts school results.Complex spans correlate with reading comprehension and maths, often more than simple spans do.

TYPICAL COUNTING SPAN BY AGE (APPROX.)

2.56

3.510

412

4.514

5Adult

Rounded from developmental studies; exact values depend on card design and scoring. Play a round to see your span on the chart.

WHAT THIS GAME TRAINS

Holding information while you work

Complex span tasks like counting span make you store and process at the same time: count each card, remember every total. That combination is what working memory is for.

corestrongsomelight

coreWorking memoryRemembering earlier counts while counting new cards.

strongSelective attentionCounting only dark-blue circles among lookalikes.

someProcessing speedCounting before the card moves on, especially on Hard.

strongCognitive controlProtecting stored totals from interference by new counts.

ON AN ORDINARY DAY

Moments that use the same skill

MOMENT 01“Multi-step tasks”Following instructions without losing your place.

MOMENT 02“Mental calculation”Keeping numbers in mind while working with them.

MOMENT 03“Reading comprehension”Holding the start of a sentence while reading the end.

INSIDE YOUR BRAIN

The brain areas doing the work

Step through each area, or tap one below. The matching marker grows on the brain; dashed markers sit deep inside.

Side view of the brain with the four lobes shaded in different colours

Based on Gray's Anatomy, fig. 728 (public domain)

AREA 1 OF 3

1Prefrontal cortexfront of the brain

The brain's control centre for planning, decision-making and holding goals in mind. It's the last region to mature, finishing in your mid-twenties.

ITS JOB IN THIS GAMEKeeps you on task and filters out distractionsDorsolateral prefrontal cortex keeps the stored totals active while you count new cards.

DID YOU KNOWIt makes up roughly a third of the human cortex, a larger share than in any other primate.

ALL AREAS

WHERE TO GO FROM HERE