Posted in ninja maths

Difficulty: ** Impressiveness: **** (Many thanks to Swar for pointing me at this one - and challenging me to explain it well!) It's surprisingly easy to square numbers near 50. Here's the recipe: 1. Find the difference between your number and 50. (If you're looking at 46, it'd be -4.

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Posted in free-for-all friday

It's that time of the week again! What's been on your mind? What's giving you a headache? As always, drop your questions in the comments box and I'll get back to you as swiftly as I can!

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Posted in in praise of..., pi

Happy Pi Day! mu-tant cow pi by janemariejett In the American date format, today is 3.14 - a pretty good approximation to $\pi$, which (as any fule kno) is the ratio between a circle's diameter and circumference. It's also the focus of most of the jokes about maths, because -

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Posted in ninja maths

The trick: someone says 'what's 7.5 squared?' and - mentally squaring in a flash - you say: 56.25. Squaring halves Squaring halves is really easy if you know your times tables. Here's the method: Take your number and find the whole numbers immediately above and below. If you're trying to

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Posted in free-for-all friday

It's that time of the week again! What's been on your mind? What's giving you a headache? As always, drop your questions in the comments box and I'll get back to you as swiftly as I can!

Read More →
Posted in core 2, graphs, integration

I was sent this by my friend and colleague TeaKay from Blogstronomy, and I've adapted the puzzle slightly to make the sums a little bit nicer. A curve has the equation $y = (x-2)^2 - n^2$. The area bounded by the co-ordinate axes and the curve in the first quadrant

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Posted in ranting

A couple of weeks ago, a news story flashed by me on twitter: 49% of the UK have slower-than-average broadband. It was followed more or less immediately by a swathe of snipey comments saying 'isn't that the definition of an average?' To which the smart-arse answer is, no, there is

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Posted in free-for-all friday

It's that time of the week again! March already! What's been on your mind? What's giving you a headache? As always, drop your questions in the comments box and I'll get back to you as swiftly as I can!

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