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Memory strategy

Chunking Trainer

A 10- or 12-digit string flashes briefly. Memorize it. We compare what you typed back to the original — and reveal how you spontaneously chunked the digits.

What makes this one different

When you type the number back, we look at where you paused or added spaces. Those pause-points reveal your natural chunk boundaries — usually 3-4 digits at a time (the famous "magical seven, plus or minus two" chunking).

Length
Display 1.5s
Accuracy —
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How you chunked

We display the original digits highlighted by your natural chunk boundaries.

History

No sessions yet.

What problem does it solve?

Chunking is the most-used memory strategy in everyday life. We naturally break phone numbers into 3–4-digit groups, IP addresses into 4 octets, dates into year/month/day. Miller's famous 1956 paper called this the "magical seven, plus or minus two" — the limit of working memory is roughly 7 chunks, not 7 individual items.

This tool doesn't test chunking as a skill — it visualizes your chunking pattern, so you can see whether you're chunking in 3s, 4s, or 5s. Most people are remarkably consistent.

Who is this for

How to interpret your results

Accuracy above 80% at 10 digits is typical. Above 90% at 14 digits is strong.

Chunk pattern typically falls in 3–4 digit chunks. If you're chunking in 5s, you might be under-using your working memory capacity.

Limitations

  • We detect chunk boundaries by where you typed spaces. If you don't use spaces, we can't visualize — but we still score accuracy.
  • Display time is fixed at 1.5s per chunk (so 4.5s for a 12-digit number in 3-chunks). Longer display times will improve scores but don't change chunking patterns.

FAQ

Why are digits so much harder than words?

Digits don't have semantic content. "5492" has no meaning to chunk around, while "apple chair ocean" has 3 distinct concepts. That's why phone numbers are harder than word lists.

Should I try to deliberately chunk?

Yes! Active chunking (e.g., 5492 → 54-92 or 5-4-9-2) is the most effective strategy. Even invented chunks work, since the limit is on chunks, not digits.