Problems
DashboardKnowledge MapLibraryDaily PuzzlesPracticeProblemsProblem SetsLeaderboard
Sign inCreate account
Library/Number Theory

Number Theory

Practice
Overview

Divisibility, primes, modular arithmetic, Diophantine equations

Practice problems
Fill the digit to make divisible by 3DIV-003
Make 15 divisible by 15DIV-015
Question 3jmc-2025-Q03
Fill the digits to make divisible by 45DIV-045
Make 10 divisible by 72DIV-072
Question 7jmc-2025-Q07
Question 15jmc-2025-Q15
Question 11jmc-2025-Q11
3 and 5 pence coinsIND-009
Sum of cubes of three consecutive natural numbersIND-001
More practice problems →

Deeper topics

  • Arithmetic functions
  • Diophantine Approximation
  • Diophantine Equations
  • Divisibility of numbers. General properties
  • Divisibility rules
  • Division with remainder. Arithmetic of remainders
  • Equations in integers
  • GCD and LCM. Mutual primality
  • Modular Arithmetic
  • Number theory. Divisibility (other)
  • Parity
  • Prime factorisation
  • Prime Numbers
  • Prime numbers and their properties
  • Products and factorials