# Why do we use decimal system? [duplicate]

Why do we use decimal system?

Some people give the answer that we have 10 fingers and it is therefore convenient for us to use decimal system, but I am not satisfy with this as I think this is too rough. Are there more reasonable or scientific explanation about why do we use decimal system or what are the advantages of using decimal system? Thank you.

-

## marked as duplicate by apnorton, Najib Idrissi, Davide Giraudo, copper.hat, TomasNov 22 '13 at 21:12

Why are you not satisfied with this? –  Chris Eagle Mar 1 '13 at 15:13
@ Chris Eagle: I though that's too rough and not scientific. –  ᴊ ᴀ s ᴏ ɴ Mar 1 '13 at 15:14
@ Jordan Mahar: Or maybe we can focus on the advantages of using decimal system. –  ᴊ ᴀ s ᴏ ɴ Mar 1 '13 at 15:18
The decimal system is not the only one used. As an example, to divide an hour I personally use sixty minutes, and to divide a minute sixty seconds. –  Sebastien B Mar 1 '13 at 15:27
"The Yuki language in California and the Pamean languages in Mexico have octal systems because the speakers count using the spaces between their fingers rather than the fingers themselves" (from the Wikipedia article on Octal [base-8] numbers). I don't believe there's a more scientific answer to this question than consideration of how our ancestors tackled the problem of counting beyond "one, two, many" –  Shaun Ault Mar 1 '13 at 16:02

There is no definite reason as to why the system chosen was the decimal system. A long time ago, every civilization had their own numeral system. The Egyptians used the decimal system, the Babylonians used a sexagesimal (base-60) system, some used a base-20 system (fingers and toes), and others counted 1, 2, 3, and anything 4 or greater was just "many". The consensus upon the decimal system was probably due to either the ease of use or that it was the first numeral system to come up with easily used symbols for arithmetic.

-

interesting question ! :)

I THINK THIS A POSITIONAL NUMBER SYSTEM .and that's of great advantage ..simple shifting the position of decimal . this is the most conventional answer ..! but somehow it seems , not that strong . we could have tried to construct a fractional system in other number systems as well !

but there are certain points i have made out :

1. if the base is more than 10 , say 20 . then if you want to use our 10 symbols (i.e. 0, 1..,9) it not possible for us to write numbers more than 9 and less than 20 or numbers more than 189 and less than 200 and numbers of similar form ) , so in that case for each unit either you will have to allot two places for digits (which will make it difficult to read a number) or you will have introduce more 10 symbols , which will make it more complex and we wont get any advantage. cause 20 is just a a multiple of 10 by 2 ..and 2 is a factor of 10 ( if the base would be 30 then , we could take it as an advantage that the problem in fixing the decimal we face while handling division by 3 could be simplified . but in that case just imagine how many symbols you will have to introduce !!! the base could be 12 . in that case dividing by three would not face any approximation problem..or if the base would be 14 then we would easily be able to divide by 7 ..but in both 12 and 14 base the problem in dividing by 5 arises. and in ancient days as our hand and toe consists of 5 fingers , i think divisibility ease for 5 was given preference ) so among systems with 10 or more than ten , the base 10 system , i.e. decimal system was given preference in different civilization , as a human mind always and everywhere think in the same direction and following our ancestors we set this as our ruling international number system mostly used !

1. now , for bases less than 10 : there is no number which has three prime factors ! among numbers 10 or less than 10 , 10 has the highest number of one digit-ed prime factors ! and for that reason in decimal system , we can properly divide any number by most number of numbers compared to all the other systems with base less than 10 .!(except 6 . which was again given less priority because 10 is a multiple of 5 )

NOTE : some say , "you can order the numbers with specific space between in decimal system .. If we can't order the number with equal interval among them , then it wont be possible to get any number line,and whole number theory will possibly be collapse then . the way co-ordinate geometry ,..vector algebra work , where ordering is very important will collapse ..! e.g in octal system 63 =77 where 64 = 100 and 65 = 101 ..so , then what's the measure of unit countable increase ? .." but , that's not a proper argument in my opinion . there we will have to consider 77+1 = 100 , 7+1=10 , 777+1=1000...and so on ,..

-
This seems mostly a rant with little actual content, apart from some incorrect things (such as 777 not being divisible by 7 in octal). –  Tobias Kildetoft Nov 22 '13 at 19:17
Well, in any positional system where $4$ is a digit you can say that $444$ is divisible by $4$. Octal $777$ is divisible by $7$, of course. –  egreg Nov 22 '13 at 19:17
okay sorry ,..! it has been edited !but the actual content thing that you just mentioned seems a stupid argument by a person who absolutely have no idea about the background philosophy of mathematics.. –  arnab Nov 22 '13 at 19:23