Featured problem
The unfinished sum
Induction
Problem archive
Featured Math Problems.
A growing archive of favourite problems from Think-Nth educators. Sometimes a calculus curio, sometimes a number-theory gem, sometimes a classic puzzle.
To submit a solution, email your working (a photo of handwritten work is fine) with the problem title in the subject line. We read every submission and publish the clearest one with the student's first name, only where permission is given.
From the archive
A friendly integral
Calculus
From the archive
Rank in disguise
Linear Algebra
From the archive
Small gaps
Number Theory
From the archive
The medical test paradox
Probability
From the archive
Power of a point
Geometry
From the archive
Diagonalise
Linear Algebra
From the archive
Lagrange's Theorem
Abstract Algebra
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