A final exam tests material from September just as much as material from April, and the topics learned first are usually the ones that have faded the most by the time the final actually arrives.
Why the oldest material is the real risk, not the newest
Students naturally over-study whatever's most recent, since it's freshest and feels most urgent. That leaves early-semester topics, naming compounds, basic sig fig rules, introductory stoichiometry, under-reviewed on the assumption they're "already known." Those are frequently the exact questions that quietly cost the most points, precisely because nobody thought to revisit them.
A cumulative review strategy that actually works
Start with a single reference sheet spanning every unit of the year instead of separate notes per chapter, so the full scope is visible in one place rather than scattered across a semester's worth of folders. Practice with mixed problem sets that combine questions from different units in the same sitting, which mirrors how a cumulative final is actually structured, rather than reviewing one unit at a time in isolation the way weekly homework does. Then deliberately retest on the earliest material specifically, since that's statistically the most likely to have decayed, rather than assuming familiarity from months ago still holds.
This is a different exercise from routine review. It's not about relearning anything, it's about surfacing what's quietly faded before the exam does that job for you, at a much worse time.
Review built around what's actually faded, not what's fresh
A real cumulative pass starts with the earliest units, the material most likely to have quietly slipped, not just a re-read of the last chapter covered.
Common questions
How far back should final exam review actually go?
The entire year, since a final is cumulative by design. Early-semester material is statistically the most likely to have faded, which makes it the highest-priority review, not the lowest.
How long before the final should cumulative review start?
Roughly three to four weeks out is enough time for a real diagnostic pass across every unit and several rounds of mixed practice, rather than a single review session the week before.
Is reviewing one unit at a time enough to prepare for a cumulative final?
Not fully. A cumulative final mixes questions across units in the same sitting, so practice should do the same. Reviewing one unit in isolation doesn't train the skill of switching between topics under pressure.