You are three chapters behind in two subjects and the exam is nine weeks away.
The first response is usually to open the earliest chapter you missed and start reading, with the intention of catching up in order. That is the wrong plan, and it is the one almost everybody chooses. It fails for a reason worth understanding: it treats every chapter as equally worth your time, which they are not, and it puts the hardest, oldest, least examinable material first, which is where the plan dies in week two.
Catching up is a triage problem. It has a method, and the method is uncomfortable because it requires deciding what not to do.
Accept the Constraint Before You Plan
The most common mistake is building a plan that requires more time than exists, then failing it in the first week and abandoning the whole thing.
Do the arithmetic honestly, once. How many study hours do you actually have before the exam? Not theoretically - actually, after school, tuition, travel, meals, sleep and the days that will disappear to things outside your control. Take that number and cut it by a quarter, because your estimate is optimistic.
Now measure the backlog against it. If you have 90 usable hours and the backlog is 140 hours of material, no schedule fixes that. You are choosing what to leave out. The only question is whether you choose deliberately or let the alphabet choose for you by running out of time in chapter nine.
Choosing deliberately is the whole skill. A student who covers 70% of the syllabus properly outperforms one who covered 100% badly, because the second one cannot produce answers on any of it. Partial coverage done well is not a compromise - it is the correct strategy under a real constraint.
And say it out loud to yourself: "I am not going to cover everything." The plans that fail are the ones that never admit this and therefore never prioritise.
Do not start at the beginning of the backlog and work forwards. That order guarantees you spend your best weeks on the oldest material and arrive at the exam having never seen the most recent chapters - which are frequently the most heavily examined and the ones your class is being taught from now.
Triage: The Order That Actually Works
Sort the entire backlog into four groups before studying anything. This takes ninety minutes and it is the highest-value ninety minutes available to you.
Group 1 - high marks, and you are close. Topics that carry substantial weight in the paper where you have some foundation already. These are the best hours you will spend all term. Do them first.
Group 2 - high marks, and you are nowhere. Heavy topics you have not touched. These need the most time and they are worth it. Second priority.
Group 3 - low marks, and you are close. Small topics you could secure quickly. Cheap marks. Do them when you are tired, because they need less of you.
Group 4 - low marks, and you are nowhere. The ones to abandon, explicitly and without guilt. Write them on a list titled "not doing these" so the decision is made once rather than nagging at you every week.
This is the Pareto principle applied to a syllabus: a minority of the topics carry a majority of the marks, and knowing which minority is worth more than any amount of diligence.
How to find the weights: past papers. Count how often each topic appears and for how many marks across three or four years. This is the most reliable information available about what matters, and it is free.
Find Where Your Foundation Actually Stops
For subjects that stack - maths, physics, chemistry, and languages to some extent - being "three chapters behind" is often not the real problem.
Work backwards until you hit solid ground. Take the chapter you cannot do and ask what it assumes. Test yourself on that. If you cannot do it either, go down again. Keep going until you reach something you can do reliably. That is your actual starting point, and it is frequently further back than the chapter you missed.
This will be further back than you want. It might be a topic from last year. Starting there feels like going backwards and it is the only route that works, because you cannot build a Grade 10 topic on a Grade 8 gap. Every hour spent on the advanced chapter while the foundation is missing produces nothing durable.
In non-stacking subjects, skip this. Social studies, biology and much of the humanities are largely modular - chapter twelve does not require chapter nine. There, go straight to the highest-weight topics and do not work backwards at all. Treating a modular subject as a stacked one wastes weeks.
Diagnose with questions, not with reading. Do not read the earlier chapter to check whether you know it. Attempt five questions from it, closed book. Reading produces a false positive almost every time.
Learn It Fast, Which Means Differently
Catching up is not normal studying compressed. Some methods scale down and others do not.
Start with the questions, not the chapter. Read the exercise questions and two past-paper questions on the topic first. You now know what the chapter is for and can skip everything in it that does not serve those. In a time-limited pass this is not laziness; it is the difference between covering a topic and reading about it.
Never read a chapter twice. One pass, then work questions. If you do not understand something during the questions, go back to that specific part. Second and third read-throughs are the most expensive comfort available and they build recognition rather than recall.
Test immediately and repeatedly. Read a section, close it, write what you remember, check. This testing effect is the highest-yield technique per minute in normal conditions and the gap widens under time pressure, because it is the only method that tells you honestly what you have got.
Do not make notes. This is the hardest instruction to follow and it is correct in a catch-up. Writing a beautiful set of notes on nine chapters consumes the whole nine weeks and produces a document you will not have time to use. Work the questions instead. Notes are for a normal term.
Get unblocked immediately rather than struggling for an hour. In normal study, sitting with a difficulty is productive - that struggle is desirable difficulty and it builds memory. Under a hard deadline the economics change: ten minutes of genuine attempt, then get the answer from a teacher, a friend or an AI tutor and move on. An hour lost to one problem is an hour that three topics needed.
Ask for the shortest explanation that lets you do the question. "I have nine weeks and I am behind - explain circle theorems in a way that lets me attempt exam questions on them today" is a better request than "teach me circle theorems". Say the constraint out loud; it changes the answer you get.
Space It Out Even When You Are Rushing
The instinct under pressure is to finish a subject completely and move to the next. It is the wrong instinct and it costs marks.
A topic studied in one long block and never revisited is largely gone in three weeks. Massed study feels efficient and produces poor retention; the same hours spread across days produce substantially more, which is the spacing effect and one of the most reliably reproduced findings in the study of learning.
So build in one revisit, minimum. Every topic gets a first pass and a short retrieval pass three to seven days later - fifteen minutes, closed book, from the questions. Not a re-read. If you have no time for the revisit, you scheduled too much material.
Rotate subjects rather than finishing one. Two or three subjects in a week beats one subject for a week. Interleaving different topics is harder in the moment and produces better discrimination between problem types, which is exactly what a mixed exam paper tests.
The forgetting curve is why the revisit is not optional. Material retrieved once decays steeply. Material retrieved twice across a week decays slowly. That second retrieval is the cheapest mark on this whole page.
Keep an Error Log From Day One
The single most useful artefact in a catch-up, and it takes a minute a day.
One page. Every wrong answer gets a line: the topic, the question type, and which of four causes it was - did not know the content, knew it and could not apply it, careless slip, or ran out of time.
Those four causes need four completely different responses. Content means revise the topic. Application means practise that question type and stop re-reading theory. Carelessness means slow down and check, and no amount of revision touches it. Time means practise against the clock.
Misdiagnosis is the most expensive mistake in a catch-up. A student losing marks to careless arithmetic who responds by re-reading the theory has spent a week on the wrong problem, and will lose the same marks in the next paper. Separating the four is straightforward metacognition - thinking about how you are failing rather than just doing more - and under a deadline it is worth more than any extra hour.
By week three the page has a pattern. Usually three or four recurring failures, not twenty. Those become the priority over new material, because a recurring error is costing you marks in every paper you sit while new coverage only adds marks in one.
Review it weekly, not daily. The point is the pattern, and a pattern needs a few days of data.
Protecting the Hours You Have
When time is the binding constraint, the quality of each hour matters more than usual, and the usual leaks are worth closing deliberately.
Phone in another room for every session. Not face down - in another room. Under a deadline the switching cost of an interruption is not just the minutes; it is the rebuilding of a multi-step problem you were holding, and holding it is what your cognitive load is already fully spent on.
Decide the output before the session starts. "Two hours of maths" cannot be finished and will drift. "The eight questions at the end of chapter 7, marked" can. A session with a finish line is the difference between two hours and two hours of work.
Study by producing, not by consuming. Every session should end with something written that you produced from memory - answers, a diagram, a worked solution. If a session produced nothing on paper, it probably produced nothing at all, however long it felt. This is what active recall means in practice.
Use the dead time for the light material. Travel, queues, waiting - that is when the low-weight recall items get done. It is not much per day and over nine weeks it is a real number.
And be ruthless about time management at the week level, not the day level. Plan Sunday for the week ahead with named outputs per session. Re-planning every evening is a decision you will lose when tired.
A Nine-Week Catch-Up Plan
Adjust the length; the shape holds.
Week 1 - triage and diagnose, study almost nothing. Count topic weights from three years of past papers. Sort into the four groups. Write the "not doing these" list. Work backwards in the stacked subjects until you find solid ground. Sit one past paper in your worst subject to find out where you actually stand. This week feels like it wasted seven days and it decides the other eight weeks.
Weeks 2-4 - Group 1, then Group 2. Question-first passes, immediate self-testing, no notes, no second read-throughs. Every topic gets its fifteen-minute retrieval pass three to seven days later, scheduled when you first cover it. Rotate between two or three subjects.
Weeks 5-6 - the rest of Group 2, and Group 3 in the tired hours. By now your error log names three or four recurring failures. Those get priority over new material, because a repeated error is costing you marks in every paper.
Week 7 - full timed papers. One per subject, marked strictly. Sort every lost mark into content, application, care, or time. Those four need four different responses and treating a care problem as a content problem is how the last two weeks get wasted.
Week 8 - only what week 7 exposed. No new topics, however tempting. The paper told you where the marks are.
Week 9 - retrieval only. Everything you covered, from the questions, closed book, spread across the week. Nothing new, nothing re-read. And normal sleep, because working memory is what a multi-step problem runs on and you need it functioning more than you need one more topic.
What Not to Do
The failures that turn a recoverable position into a bad result.
Do not start at chapter one and work forwards. It is the most natural plan and the worst one.
Do not make notes. Nine weeks, nine chapters, one beautiful unused document.
Do not try to cover everything. The plan that includes all of it is the plan you abandon in week three, and abandoning it costs you the topics you would otherwise have secured.
Do not cut sleep. Sleep is when learning is consolidated, so trading it for study hours removes the process that would have made the hours count. It is the worst trade on the table and it is the one students under pressure reach for first.
Do not compare with classmates who are not behind. Their plan is not yours and their position is not yours. Comparison here produces panic, and panic produces the chapter-one-forwards plan.
Do not hide it from your teacher. This is the one students get wrong most often. A teacher who knows you are three chapters behind can tell you which of those chapters actually matter in the paper, which is precisely the information the whole triage depends on. It is a two-minute conversation and it is the highest-value one available to you.
Do not conclude it is too late until you have done the arithmetic. Nine weeks is a lot of hours. Most students who feel it is hopeless have never counted, and the counting is usually more encouraging than the feeling.
The Short Version
Being behind is a triage problem, not a diligence problem. The plan that fails is the one that starts at the beginning of the backlog and covers everything in order, because it spends your best weeks on your oldest material and never admits that something has to be left out.
So count your real hours, count the topic weights from three years of past papers, and sort the backlog into four groups - including one you explicitly abandon. Work backwards in the stacked subjects until you find solid ground, and go straight to the heavy topics in the modular ones.
Then read each topic once, question-first, test yourself immediately, make no notes, and get unblocked in ten minutes rather than an hour. Schedule one fifteen-minute retrieval pass for every topic three to seven days later - that second pass is what makes the first one count.
And tell your teacher where you actually are. They know which chapters matter, which is the one piece of information you cannot get from a past paper on your own.