The Feynman Technique for Technical Subjects
Explaining the concept of inertia in your own words is one thing. Explaining why integration by parts works, or where Newton’s second law comes from in a specific problem, is quite another. The Feynman technique applied to math and physics demands more than simplifying with analogies: it demands being able to reconstruct the procedure step by step, without memorizing it like a recipe. Here’s how to adapt it without losing rigor.
Why technical subjects need a variant of the method
In history or biology, explaining in simple words is usually enough to detect gaps. In math and physics the problem is different: you can recite a formula perfectly and not understand what it represents, or solve an exercise following memorized steps without knowing why those steps are valid. The Feynman technique in exact sciences must always include the question “why this step and not another?”, not just “what does this say?”.
If you want to review the basics of the method before adapting it, this article on the 4 steps of the Feynman technique explained gives you the general framework to build this technical version on.
The mistake of treating formulas as sentences to memorize
A formula isn’t a sentence you memorize like a historical date. It’s the compressed conclusion of a reasoning process. When you apply the Feynman technique to math superficially, you tend to explain the formula instead of explaining where it comes from. The real test of understanding isn’t saying “velocity is the derivative of position”, but being able to explain why deriving position gives you velocity, using a concrete situation: a car, a graph, a motion you can visualize.
- Ask yourself what problem that formula originally solves.
- Try to derive or justify it with a simple particular case.
- Explain what would happen if you changed a variable, without using the formula, just with logic.
Explaining the procedure, not just the result
In a physics or math problem, the final result is the least important thing from a learning standpoint. What you need to be able to put into words is the procedure: what information you had, what you decided to do first and why, which mathematical tool you chose and which alternatives you discarded. Take an already solved exercise and, without looking at the solution, explain each decision out loud as if you were teaching someone who has never seen that type of problem.
If you notice you get stuck justifying a specific step — not remembering the formula, but explaining why it’s used there — you’ve found exactly the gap you needed to locate.
Feynman in physics: from concept to equation
The Feynman technique for physics works best when it reverses the usual study order. Instead of starting with the equation and looking for an example to illustrate it, start with the physical phenomenon and try to reconstruct the equation by explaining what each term represents. Why does that factor appear in the law of conservation of energy? What does that negative sign physically mean? Explaining the physical meaning of each symbol, not just its name, is what distinguishes understanding from remembering.
A useful technique: choose an everyday thought experiment — a falling ball, a stretching spring — and explain the phenomenon first with plain words, and only afterward translate that explanation into mathematical notation. If the translation is hard for you, the problem isn’t physics, it’s that you don’t yet master the language that describes it.
Simplifying without losing precision in exact sciences
Simplifying in math and physics has a clear limit that doesn’t exist in other subjects: you can’t invent an analogy that contradicts the rules of the system. You can say a derivative is “the speed at which something changes”, but you can’t simplify to the point of saying something mathematically false just because it sounds clearer. The key is to simplify the language, not the content: use simple words to describe exact relationships, without sacrificing the accuracy of those relationships.
When you’re unsure whether your simplification is still correct, try applying it to a limiting or extreme case of the problem. If the simplified explanation still holds there, you’re on the right track.
Practicing with varied problems, not the same type repeated
A typical mistake when applying the Feynman technique to technical subjects is always explaining the same type of exercise until mastering it, and assuming that means understanding the whole topic. Solving technical problems requires exposing yourself to variations: change the data, change the context of the statement, reverse what’s given and what’s unknown. If you can only explain the “typical” problem the teacher used, your understanding is still fragile.
Explain out loud at least three different variants of the same concept before considering that you truly master it.
Using flashcards to lock in key formulas and procedures
The Feynman technique tells you whether you understand something, but it doesn’t guarantee you’ll remember it weeks later under exam pressure. For that you should combine it with spaced active review. A simple way is to create flashcards where the question is “why is this formula used here?” or “what does this step of the procedure represent?”, instead of flashcards that just ask you to repeat the formula from memory.
For this, Aevoran’s students create their own question/answer flashcards; automatic spaced repetition based on correct and incorrect answers fit well: turn every Feynman explanation you make about a procedure into a flashcard, and let spaced repetition decide when it’s time to review it again.
Detecting if you understand a procedure or just recognize it
Recognizing a type of problem isn’t the same as understanding the procedure that solves it. Many students confuse the two because, when seeing an exercise similar to one already practiced, their brain triggers the correct pattern without real understanding behind it. To check this, cover the original problem statement and explain the general procedure you would apply to “any problem of this type”, without having the specific example in front of you.
If in this process you find a point where your explanation becomes vague or you rely on “that’s just how it’s done”, you’ve located exactly the part of the procedure you need to strengthen.
Frequently asked questions
Does the Feynman technique work the same for math as for physics?
The underlying logic is the same: explain in simple words to detect gaps. The difference lies in the focus. In math it’s best to focus on justifying each logical step of a proof or procedure. In physics you should also connect the formula to a concrete phenomenon you can visualize. Both versions require going beyond reciting the formula from memory.
How do I apply Feynman if the exam is about solving problems rather than explaining theory?
The trick is to explain the procedure out loud before solving the problem on paper, and to verbalize why you choose each mathematical tool at each step. If you can justify your decisions without looking at notes, that understanding will translate into solving new problems more fluidly, not just the ones you’ve already practiced.
How much time should I spend explaining each formula with this method?
There’s no fixed universal number, but a useful reference is to spend enough time to explain the formula, its origin, and an applied example without getting stuck three times in a row. If after several attempts you keep getting stuck at the same point, that’s the real indicator that you need more time, not a fixed timer.
Is it a problem if my simplified explanation sounds different from the textbook’s?
No, as long as the content remains correct. The goal of the method isn’t to memorize the textbook’s wording, but to be able to explain the same mathematical or physical relationship in your own words. If your simplified version still holds in limiting cases and doesn’t contradict any rule of the system, it’s just as valid as the original text’s version.
Should I memorize formulas even if I understand where they come from?
A certain level of memorization always helps because it speeds up problem-solving under time pressure. But that memorization should be built after understanding the origin of the formula, not instead of understanding it. Reviewing with spaced repetition flashcards once you’ve already understood the procedure is an efficient way to lock in that memory without falling into empty memorization.