Work through the levels in order. Type your answer and press Check — open the worked solution if you get stuck. Answers like -6, 3/4 or 0.25 are typed exactly as shown.
Level 1 · Warm-up
1 What does the forgetting curve describe?
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The fading of memory over time when material is not retrieved. Each review flattens the curve.
2 In the three-pile system, how often is the "struggling" pile reviewed?
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Daily. Getting there: every 2-3 days. Solid: weekly, then monthly.
Level 2 · Core
3 Your ten-minute "review" consists of re-reading your notes. Why does this not count?
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Re-reading is recognition. A review must be retrieval: close the book, produce the answer, then check.
4 You have just been taught a brand-new method today. Should you practise it blocked or interleaved?
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Blocked first to build the execution, then move it into the interleaved mix to build method selection.
Level 3 · Challenge
5 A student's blocked practice score is 90% but their interleaved score is 65%. What does this tell you?
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Execution is solid; method selection is not. The exam mixes topics, so the 65% is the honest number — and interleaving is how they fix it.
6 Why do the review gaps EXPAND (same day → 1 day → 3 days → 1 week) instead of staying equal?
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Each retrieval flattens the curve, so the memory survives longer and the next review can safely be further away.