Posted in probability.

* Thanks to Barney Maunder-Taylor for the problem In Alex's Adventures In Numberland, the author - Alex Bellos - makes a big production of getting one of his parents to pretend to toss a coin 20 times and the other to actually do it, then tell which one is which.

Read More →I'm going to run a little experiment for a while. Every Tuesday until the exams, I'm going to put out a ten-question quiz on one of the A-level modules. I'd love to have feedback on whether you find them useful, how I can make them better, and what else I

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Posted in ninja maths.

The sun is setting outside the dojo. The Mathematical Ninja's student knows this, for he is looking out of the window. At some point, he notices the compass point a fraction of a centimetre from his eyeball. "Pay attention," says the Mathematical Ninja. "What does this add up to?" He

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Posted in silly questions amnesty.

Come on now, hand over any silly questions you might have. No names, no pack-drill!

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Posted in geometry.

There are some problems that trouble so many people for so long that they become 'classics'. Things like Fermat's Last Theorem (which lasted 350-odd years without a proof), how to factorise big numbers (still waiting) and proving the parallel postulate from the other Euclidean axioms (about 2,300 years before people

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Posted in ninja maths.

A few weeks ago, the Mathematical Ninja explained how to divide by 9 on the fly. This week, it's multiplying that's on his mind - a more common thing to have to do. The multiplying method is easier, too. It's just a case of adding and taking away - and

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Posted in silly questions amnesty.

St David's Day! Any questions? What would happen if you put 20,000 leeks under the sea? How do you get two whales in a mini? That sort of thing. The sillier the better.

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