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A proof with a hole
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Duplex difference Sudoku
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Mystery Christmas theft
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Losing a pound
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Chocolate egg or chocolate bunny? Dark chocolate or white?
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Writing the unwritable: up-arrow notation
How to write down unimaginably large numbers using just a few symbols.
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When things get weird with infinite sums
What is 1-1+1-1+1-1+...? How infinite sums challenge our notion of arithmetic.
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Maths in a minute: Writing infinite sums
How to write a sum that's infinitely long.
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Mathematical mysteries: the Goldbach conjecture
Can every even number greater than 2 can be written as the sum of two primes? It's one of the trickiest...
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Mathematical mysteries: Hailstone sequences
Here's an easy game that leads you straight to an unsolved question in maths.
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The philosophy of cosmology
Can philosophy help explain our Universe?
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