# Pi-Day

Any blogger who doesn’t realise that 14th March can’t be paying attention.  We’ll need to forget that in the UK we write 14/3 rather than 3/14, because this year is of course special, since Sunday will be 3/14/15.

We all know the usual approximations of       22/7    3.14      3.142

All these are good enough for most of us; I can’t think I’ve ever need to know that the first eight digits are 3.1415926, but one of my old pupils Johanna kindly created the mnemonic I’ve used for 25 years:

And that’s all I have to offer as a contribution to Pi-Day.  In any case, the 15th is Mothering Sunday and I’ll have other commitments.

Footnote: I came across this limerick for pi.  I couldn’t decide whether it fits into the piece on limericks, or the one about pi.  Easy; just put it in both:

It’s a favourite hobby of mine
a new value for pi to assign
I would fix it at three
because it’s easier, you see
than three point one four one five nine
(3.14159)

.

### 4 responses

1. It took me a few seconds to realize that I needed to count the number of letters in each word. It does makes a good way to remember pi.

1. Given that people have written whole stories in which “i” is the only vowel or which don’t use the letter “e” (the first known example dates back well before Jesus) I’m certain people have done much longer pi mnemonics. There’s a bit of a snag where a zero appears, but fortunately that doesn’t happen until you’re thirty-plus digits in.

2. There’s a 10000 words story out there for the first 10000 digits of pi…

3. I don’t doubt it for a moment, though I’ve no wish to check it for accuracy. People have put ridiculous amounts of effort into creating passages which follow what you’d think were impossibly demanding rules.

Try this sentence, where the last letter of one word is the first letter of the next:

“Old Doc came even nearer, revealing gold dentures, smiling grimly.

And this goes one better: