Number Theory practice, graded like a real exam
Divisibility, primes, gcd, modular arithmetic. Number Theory rewards precision and repetition more than almost anything else on a probability & counting course — it is exactly the kind of topic where working through twenty varied problems beats re-reading the chapter a third time. QED gives you an endless supply of exam-grade number theory questions and marks every answer the way an examiner would, so each attempt actually teaches you something.
✓ First questions free · no card · no setup
What a Number Theory question looks like
In a QED session, an exam-level number theory question might ask you to run the Euclidean algorithm for a gcd, solve a linear congruence and state the full solution set mod n, or prove a divisibility claim.
Every question carries a hidden marking rubric. You answer in real notation, and QED marks each criterion separately — awarding partial credit and showing a full worked solution, so you learn from the marks you dropped.
Every Number Theory subtopic
13 focused guides, each with the method, a worked example and the mistakes that cost marks. Work through them in order or jump to your weak spot.
- 1Divisibility & the division algorithm
- 2Primes & unique factorisation
- 3gcd, lcm & the Euclidean algorithm
- 4Modular arithmetic & congruences
- 5Solving linear congruences
- 6Fermat’s little theorem
- 7The Chinese remainder theorem
- 8Modular inverses & fast exponentiation
- 9Euler’s totient φ(n) & Euler’s theorem
- 10Base-b representations & digit arguments
- 11RSA & modular exponentiation in cryptography
- 12Wilson’s theorem & primality testing
- 13Linear Diophantine equations ax + by = c
Why students use QED for Number Theory
Not another chatbot that blesses whatever you type. QED is built for deliberate practice — the way maths actually sticks.
Practice that never runs out
A textbook gives you a handful of number theory exercises with the same worked answers everyone has seen. QED generates unlimited fresh number theory questions at warm-up, exam and challenge level, so you can drill a weak spot until it is automatic — not until you run out of problems.
Marked like an examiner, not a checkbox
Most tools just say “correct” or “wrong”. QED marks your number theory answer against a point-by-point rubric, awards partial credit, shows exactly where the reasoning slipped, and gives a full model solution. A right answer with the wrong argument still loses the argument marks — just like a real exam.
A library you can come back to
Every number theory question you generate is saved, organised and re-takeable as a timed exam. Your mastery is tracked per topic, so you always know whether Number Theory is exam-ready or still needs work — and you can export any question or exam report to PDF.
Write maths the way you actually write it
Answer in real notation with a one-tap symbol palette and a visual equation editor, drop in truth tables, or photograph a handwritten page — QED converts your handwriting to clean LaTeX. No fighting with syntax to show what you know.
How practising Number Theory works
- Generate a fresh questionPick Number Theory and a difficulty — warm-up to build intuition, exam level for the real thing, or challenge for multi-step problems. A new, verified question appears in seconds.
- Answer in real notationType it, build it in the equation editor, lay out a truth table, or photograph your handwritten working and let QED convert it to LaTeX.
- Get marked criterion by criterionQED scores every rubric point separately, awards partial credit, flags where the reasoning slipped and shows a full model solution. The question is saved to your library to retake any time.
Related topics
Building a full picture of probability & counting? These pair naturally with Number Theory.
Number Theory — frequently asked questions
Is QED good for revising Number Theory before an exam?
Yes — that is exactly what it is built for. Generate number theory questions at exam level (or push up to challenge), answer them under timed exam mode, and get marked against a rubric with a full model solution. You can retake any question and watch your Number Theory mastery climb until it is solid.
How many Number Theory questions can I practise?
As many as you like. QED generates fresh number theory problems on demand instead of recycling a fixed set, and every question you make is saved to your library to retake for free. New accounts start with free question generations, no card required.
Do I need to know LaTeX to answer Number Theory questions?
No. There is a one-tap palette for symbols, a visual equation editor, and a truth-table builder — and you can photograph a handwritten solution and let QED convert it to LaTeX for you. You concentrate on the maths, not the typesetting.
Ready to make Number Theory exam-proof?
Generate your first number theory questions free — no card, no setup. Practise until it is second nature.
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