## Friday, 1 August 2014

### The best number...EVER...27!

It's a well known fact that my favourite number is 27! All my students know this (or at least they should by now) and so I decided, on putting up some new displays in my classroom, that one would just have to be based on the best number ever.
So, on going into school today, I removed my existing displays, re-backed and bordered them and then put up the 27 display. Here it is...

Ta da! My new 27 display - details of all the facts etc below...
Here are the other displays (including my room divider which I plan to make a bit more use of this year).
View from the back of the room. Obviously it's a bit of a mess at the moment as there are staples and bits of old backing paper all over the floor, tables and chairs moved about so I could get to the displays etc. It'll all be cleaned and moved back to normal over the INSET days in September.

As for the contents of the 27 board, here are all the great facts that make it the best number ever...
(all of these appear on the board in one way or another)

27 is (UPDATE...almost) the only number where the sum of its digits is equal to the sum of its prime factors (@srcav has since informed me [correctly] that 4's digit is also equal to the sum of its prime factors)!
Batman first appeared in the 27th issue of Detective Comics
The Chemical Element with an atomic number of 27 is Cobalt
Of the 365 numbers that appear in the Bible 27 of them are prime
the 27th digit of Pi is 8
the number 27 appears in the digits of Pi for the first time in positions 28 and 29
The number on Heathrow Airport's runways is 27 as it is on a bearing of 270 degrees
The 27th Pokemon is Sandshrew
27 squared is 729
the Prime Factorisation of 27 is 3 x 3 x 3 or 3 cubed
27 in French is vingt-sept, 27 in German is siebenundzwanzig, 27 in Spanish is veintisiete, 27 in Chinese is er shi qi
My watch, which has the number 27 (and only the number 27) on it, is based on the 'Club 27' generation of famous musicians, all of which died aged 27
There used to be a 27th letter of the Alphabet (&)!
In Roman Numerals the number 27 is XXVII
In words the number 27 is twenty seven
27 appears LOADS in the movies including in Back to the Future (on the time dials in the Delorian), in Elf (the number of the taxi), in 27 dresses and on the front door to Scott Pilgrims' house. All of these are just a few of the examples. I included a QR Code on the display that scans to a web page with all the documented appearances of the number 27 in the movies.
http://27.chrismore.com/2009/11/movies.html <-- link here

There's also a QR Code that scans to the Wikipedia page on Runways to explain the '27' at Heathrow.
There are then some diagrams I drew on 1cm squared paper of a rectangle, triangle and trapezium all of whose areas are 27 cm squared.
http://en.wikipedia.org/wiki/Runway <-- link here

There are still a few gaps and so I intend to fill these with some laws of indices using 27. The number appears quite frequently in exams due to it being a cube number and so will include some 27 to the power two thirds etc to the display in September.

Other than that, the reason it's my lucky number is that it was the house number I grew up in (and where my parents still live). It appears in my e-mail address and I now live at Flat 27 (we were given a choice of 27 on the 2nd floor or 120 on the 6th floor - It wasn't really a choice)!

I wonder if there are any other teachers out there that have a display of their favourite number? If there are it'd be great to see a picture - tweet me @mrprcollins or comment below!