Posted in fractions, ninja maths.

The final installment, the big reveal: why does the ninja trick of multiplying by 77 and finding the nine’s complement work? My friend, that is an excellent question. The reason is this: $77 \times 13 = 1,001$. And it turns out, 1001ths are not all that hard to work out.

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Posted in silly questions amnesty.

The answer is eleven! The silly question was 'how many sleeps until Isaac Newton's birthday?' Do you have a silly question?

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Posted in armageddon, ranting.

I made the mistake of clicking on this link. So it is logical, is it not, that the Crystal Vortex is the Epi-Centre Heart of the Ascension on the 12-12-12. No, Mr Tyberonn, no it isn’t logical. It may be a masterclass in sciencey-sounding… I was about to say ‘bullshit’,

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Posted in fractions, ninja maths.

This is the second of a three-part series about working out thirteenths. In the first part, you learned that the first step of finding thirteenths was to multiply by 77. The second part is to work out the nine’s complement of one less than your number. What’s the nine’s complement?

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Posted in silly questions amnesty.

It's the first Silly Questions Amnesty of December - what's on your mind?

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Posted in talks.

I'm very happy to be able to reprise my talk about the Curious Maths of Alice in Wonderland at Imagine Books on Saturday, December 15th at 1pm. Here's the abstract: "Whatever good meanings are in the book, I'm glad to accept as the meaning of the book." - Lewis Carroll

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Posted in exam technique, ninja maths.

If you’ve been following the Flying Colours Maths blog for any length of time, you’ll have noticed that every Monday, there’s a new Secret of the Mathematical Ninja, a quick tip or trick for coming up with a more-or-less accurate estimate of some crazy sum you might see in your

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Posted in fractions, ninja maths.

I’ve always liked the number 13, perhaps because it’s got a bad reputation. However, until Matt Parker’s recent ZOMG tweet, I couldn’t do thirteenths in my head. If you asked me ‘what’s 7/13?’, I’d have screwed my face up and said “a bit more than a half.” Now I know.

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