5.Babylonian numbers 1-9

the Babylonians counted in Bay 60 just like we count minutes and seconds and degrees of angle in 60s but they used a different set of numerals different set of signs than we do in order to write the numbers so number one is a vertical wedge on the play and we'll represent it like this whereas this triangle here is the deepest part of the wedge in the clay so one vertical mark in the clay is one and they're not surprisingly two vertical marks is two three and then we get something slightly different because we just keep doing like this then we end up with lots of vertical lines and sometimes it's difficult just to be able to look at them and see how many their lines there are in the number so after three the scribes would write for as three wedges on top and a big one underneath five is like this and here's six so you can see you don't really have to count the number of wedges in the sign six you can just look at them and see that there are two rows of three and so it goes on so that seven is three plus three plus one and you can guess what eight and nine are going to look like is eight and nine three threes so those are all the unit signs one two nine but you don't keep doing that up to 59 you have another set of signs for the tens and they look rather different they're not vertical marks but these diagonal corner wedges in the clay for there is 10 and again that's the deepest part of the wedge in the clay so you can guess what's what 20 is going to be like and 30s are we going to start of the same principle as we did for the unit when we come to writing 40 and 50 so that's 43 and 110 wedges and that's 50 and we don't need a 60 sign because again if you think about digital clocks and other ways in which we write based 60 then when we come to write this 60 we go back to writing our ones again now so let me give you an example of that so if we think about the number 84 in the in the decimal system we think of that as eight tens and four units in a base 60 system system if we're thinking for instance like eighty four minutes well that's one hour and 24 minutes three represent patters one and then 24 so there's our 162 tens and four units and just like the modern decimal number system the order in which the numbers are written matters is what we call a positional number system so this because this is two that this one is to the left of these two tens we know that this one must be bigger than the 210 that is it must be a sixty and not a unit so if we write for 60s that's two hundred and forty and two tens two hundred and sixty and one unit two 261 so we can see here the positional base 60 system at work you

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Keywords: Babylonian, numbers

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Length: 5min 0sec (300 seconds)

Published: Fri Mar 18 2011