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Base Numbers
Posted: Fri Mar 25, 2011 8:44 pm
by Gavin Strachan
Does anyone have any practical examples of using base numbers? Base 2 is binary - computers easy.
Base n?
Mr Sad

Re: Base Numbers
Posted: Fri Mar 25, 2011 9:02 pm
by Rob Thompson
Hexadecimal is also used in computers, most notably graphics displays
Re: Base Numbers
Posted: Fri Mar 25, 2011 9:04 pm
by Andy McCulloch
Many years ago, when programming in machine code, it was useful to know how to use base 4, base 8 and base 16, the grandly named hexadeximal, was all but essential.
Re: Base Numbers
Posted: Fri Mar 25, 2011 9:06 pm
by Paul Sanders
Lots of things are still bought and sold in dozens. Eggs for instance.
Re: Base Numbers
Posted: Fri Mar 25, 2011 9:25 pm
by Matthew Turner
I understand base 24 and base 60 are used every day

. An explanation of base 60 is that there are 12 sections on the fingers and folding the fingers on the other hand allows you to count 5 lots of 12. This method may have been used by shepherds during Roman times.
Re: Base Numbers
Posted: Fri Mar 25, 2011 9:41 pm
by Andy McCulloch
Again I seem to remember that base 60 came from the Babylonians, look how many factors it has.
A pupil stumped me years ago by asking why we had 60 minutes in an hour and 60 seconds in a minute, and I had no idea.
A little research then revealed that the name came from the Latin when the Romans, who seemed to hoover up everything, called the divisions 'pars minutiae' and 'pars secundus'.
Also used in geometry, minutes and seconds of arc.
Re: Base Numbers
Posted: Fri Mar 25, 2011 10:15 pm
by Gavin Strachan
One interesting point is that say the dozen 12 base: 13 doesn't exist so this would = 10
So if you ask for a bakers dozen you get 10 though end up with 13 dernary rolls.

Re: Base Numbers
Posted: Fri Mar 25, 2011 10:24 pm
by Matthew Turner
From horse racing we use bases 220, 8 and 105.
Re: Base Numbers
Posted: Fri Mar 25, 2011 10:31 pm
by Matthew Turner
How about base 92,955,807.27? I haven't used this one since yesterday.
Re: Base Numbers
Posted: Fri Mar 25, 2011 10:36 pm
by Rob Thompson
Gavin Strachan wrote:One interesting point is that say the dozen 12 base: 13 doesn't exist so this would = 10
So if you ask for a bakers dozen you get 10 though end up with 13 dernary rolls.

actually, in base 12, 13 would be written as 11. 12 is 10
Re: Base Numbers
Posted: Fri Mar 25, 2011 10:52 pm
by Brendan O'Gorman
I seem to recall reading somewhere that counting in twelves had greater practical use than tens because 12 could be split into more whole numbers than 10. Three quarters of 12 is 9, half of 12 is 6, one third is 4, a quarter is 2, and a sixth is 2. Try that with 10!
Re: Base Numbers
Posted: Fri Mar 25, 2011 11:24 pm
by PeterTurland
Hex is amazing because 16 is both 2^4 and 4^2 and as far as I know, no other number has this property, for instance 2^3 <>3^2 this probably makes 16 very special!
Usually you work out the nth number of pi by knowing its previous value, ie you have to work out all the previous values of pi to know the nth value of pi, there is an equation to work out the nth term of pi without knowing its previous value. Here is the kicker it only works in hex!
Plouffe formula
It gets better - there are 20 different amino acids constructed from a base four arrangement ACTG, 4^3 = 64, 64 = 16 X 2 X 2.
Where this starts to get interesting is when we consider morphogenesis, ie start out with one cell and end up with elephants, understanding the mathematics of morphogenesis, in the context of genetics, will teach us the mathematics of life.
And explain why most chess players are useless at explaining themselves

Re: Base Numbers
Posted: Fri Mar 25, 2011 11:24 pm
by Matthew Turner
Times tables are much easier in base 12
multiples of 3
3 6 9 10 13 16 19 20 23 26
multiples of 4
4 8 10 14 18 20 24 28
multiples of 6
6 10 16 20 26 30
multiples of 8
8 14 20 28 34 40
multiples of 9
9 16 23 30 39 46 53
multiples of ten, eleven, twelve and thirteen also follow nice sequences
Re: Base Numbers
Posted: Sat Mar 26, 2011 12:35 am
by Peter Rhodes
You can add Crash Dumps and Symmetrix Device ID's (
http://en.wikipedia.org/wiki/EMC_Symmetrix) to your list of practical examples in Hex.
Re: Base Numbers
Posted: Sat Mar 26, 2011 1:06 am
by Jon D'Souza-Eva
And of course 6 x 9 = 42 (base 13)