Free Calculus Help
Calculus has a reputation for being conceptually hard. In practice most lost marks are algebra errors inside correct calculus — which is good news, because that is a fixable problem.
Why calculus grades actually slip
Mark a failed calculus exam honestly and the pattern is usually the same: the student set up the derivative or integral correctly and then lost the marks simplifying. The calculus was right. The algebra underneath it was not. If that describes your paper, more calculus revision will not help you — a week on algebraic manipulation will.
The genuine conceptual difficulty is narrower than it feels, and it is mostly about what the operations mean: that a derivative is a rate, that an integral is an accumulation, that the Fundamental Theorem says those are inverses. Students who never build that picture end up memorising a hundred disconnected rules, which does not survive an exam that rephrases anything.
Related-rates and optimisation word problems deserve separate mention: they are where the course's hardest marks live, they are predictable in form, and they are the most commonly skipped revision topic. Working ten of them is worth more than re-watching a chapter.
Free resources worth your time
Everything below is free to use without payment. The note on each one says when to reach for it, because the usual problem is not a shortage of material — it is picking the wrong kind of material for the stage you are at.
- Khan Academy — Calculus 1 Free course Strong practice engine. The value here is the exercises, not the videos.
- 3Blue1Brown — Essence of Calculus Video channel The best explanation of what calculus actually means that exists for free. Watch early; it is intuition, not exam technique.
- MIT OpenCourseWare — 18.01 Single Variable Calculus Free course A complete MIT course with exams and solutions. The problem sets are harder than most courses — use them to find out whether you really know it.
- OpenStax — Calculus Volume 1 Free textbook Free and thorough, with worked examples. Volumes 2 and 3 cover the later sequence.
- Professor Leonard Video channel Full lectures with every algebraic step shown — useful precisely because the algebra is where marks go missing.
What to do with the time you actually have
If you have the rest of the term
Watch 3Blue1Brown's Essence of Calculus early, not as revision. It takes a couple of hours and it builds the picture that makes everything afterwards cheaper to learn. Then do problems — the picture alone does not earn marks.
If you have a week
Separate your errors into "didn't know the method" and "knew the method, botched the algebra". Those need completely different weeks. Then work past papers under time pressure, because calculus exams are usually tight on time.
If you have tonight
Drill the derivative and integral tables to instant recall, then work the three most likely word-problem setups. Do not start a new technique tonight.
Work out what you actually need first
Before you spend a weekend on this, get the number. If the final is worth 20% and you are sitting at 88%, an A needs 98% and a B needs 48% — those two facts call for completely different weeks. Run your real numbers through the final grade calculator, then come back and pick the plan that matches the gap. The finals-week triage guide covers how to split time across several courses at once.