Revision and Retention

Recall of something learned once drops steadily over the following days without review. Each time you deliberately bring it back to mind, the next drop is slower and the memory lasts longer.

The practical reading: a topic studied once and never revisited is, by exam day, mostly gone. Revision is not an optional polish at the end - it is what converts a week of learning into marks two months later. Plan the reviews at the same time you plan the learning.

Recognition is not what the exam tests. The moment of struggling to retrieve an answer is what strengthens the memory, so the uncomfortable method is the one that works.

A strong form of recall is the teach-it-back test: explain the topic aloud as if to a student. Wherever you stumble or hand-wave is exactly what goes on the next revision list.

Review a new topic at expanding intervals rather than in one block: once about a day later, again after roughly three days, then about a week, then a fortnight. Each successful recall lets you push the next review further out.

Keep it lightweight. A review is a few minutes of recall from a summary sheet plus two or three problems, not a re-study of the chapter. Track which topics are due; a simple dated list or a flashcard app is enough. A topic that fails its recall check drops back to a short interval.

• One page per topic. Condense each topic to a single sheet: the formulas, the rules, the standard traps, and one representative solved example. If it does not fit on a page, it is not a revision sheet yet.
• Flashcards for atomic facts - a formula, a rule, a conversion, a definition. One idea per card, question on one side.
• A fixed weekly slot to cycle the sheets. The 20 percent revision block from your study plan is where these live.
• Build the sheet as you learn the topic, not the week before the exam. Making it is itself a strong recall exercise.

Practising one topic in a long unbroken block (all percentages, then all ratios) feels efficient and produces a weaker result than interleaving - mixing question types within a session.

Interleaved practice is harder because you must first work out which method a question needs, then apply it. That extra step is exactly the skill a mixed exam paper demands. Block practice while first learning a method; switch to interleaved sets once the method is in place, and lean on them heavily in the last month.

• Weeks 4 and 3 before the exam: learning is nearly done. Most time goes to full mocks, the error log, and cycling the summary sheets. Learn only to plug a specific leak a mock has named.
• Week 2: mocks plus targeted revision of the topics that still show up in your error log. Interleaved sets only.
• Last 10 days: no new topics. A topic you have not started by now costs certain revision time for an uncertain few marks. Consolidate: sheets, flashcards, light mocks, and timing rehearsal.
• Last 2 days: taper. Skim sheets, sleep normally, and rehearse the exam-day routine rather than cramming.

• A topic learned once and not revisited is mostly gone by exam day; schedule reviews when you schedule the learning.
• Active recall - shut the page and retrieve - beats re-reading, which only builds recognition. Teach-it-back exposes the gaps.
• Space reviews at expanding intervals: about a day, then three days, then a week, then a fortnight; a failed check drops back to a short interval.
• Condense each topic to one page of formulas, rules, traps and one example; use flashcards for atomic facts; keep a fixed weekly slot.
• Interleave question types once the method is learned; block practice only while first learning it.
• Final month: mocks plus sheet cycling; last 10 days no new topics; last 2 days taper.

Pick the best response and give a one-line reason.

1. You have re-read the ratio chapter three times and still miss the questions. Best use of the next hour?
2. You learned a new reasoning topic today. When should its first review be?
3. Your notes run to about 40 pages per subject. What is the problem, and the fix?
4. Ten days to go and you have not started one whole topic. Begin it now?
5. You tend to revise only the sections you already score well in. Why change that?
6. For the last month, is blocked practice (all of one type) or interleaved practice (mixed) the better choice?

Answers. 1 Do 15 to 20 mixed ratio problems closed-book, then review only the ones you missed - retrieval, not another read. 2 Within about a day, then space it out (roughly three days, a week, a fortnight). 3 They are too long to revisit; condense each topic to a one-page sheet of rules, formulas, traps and one example. 4 No - in the last 10 days consolidate what you know; a new topic trades certain revision time for an uncertain few marks. 5 Marks are lost in the weak sections, so revision time should be weighted toward them and protected by a fixed slot. 6 Interleaved - it matches a mixed paper and trains you to pick the right method under uncertainty.