TITLE: what base number system is the hebrew language?
QUESTION [8 upvotes]: In the hebrew bible, there number system is based off of hebrew letters. There is a single digit used going all the way up to 10, then it uses two digits... Untill it gets to 20, which is a single digit again. The actual hebrew numbers go in sequence of: 1,2,3,4,5,6,7,8,9,10,20,30,40,50,60, 70, 80, 90, 100, 200, 300, 400. What base of numbers would that be+

REPLY [3 votes]: The Hebrew numerals constitute a decimal system, however it's different from the Arabic decimal system in that the symbols do not recycle through all the orders of 10^n. So a symbol's position in a string does not impact the symbol's value. Because of this, the system, does not scale elegantly. It's not really used for doing math (generally) nor representing very large numbers (though they could be if a system of infinite extension were devised). Let vector A = [1,2,3,4,5,6,7,8,9], then, left to right, the numerals B = [ט,ח,ז,ו,ה,ד,ג,ב,א] are (10^0)A respectively; and are the only symbols ever in the 10^0 place . Numerals C = [צ,פ,ע,ס,נ,מ,ל,כ,י] correspond to (10^1)A, and D = [ץ,ף,ן,ם,ך,ת,ש,ר,ק] (alternatively, D = [תתק,תת,תש,תר,תק,ת,ש,ר,ק]) to (10^2)A. These basic symbols have been extended somewhat with apostrophes and dots, but is still quite limited in the range of represented values. Zeroes do not need a symbol in this system, because it is not dependent on position. If you were using Hebrew numerals as a tool for calculation, cognizance of the decimal exponent would need to be taken, as well as how the elements of B, C, and D scale from one vector to another through the various operations. 
So, that was the symbols, but base 10 clearly shows up in the naming convention, too. Names for ones, tens, hundreds, and thousands. They cycle just as regularly as you would expect. The naming does get a little strange, though, with names like shesh me'ot elef usheloshet alafim vachamesh me'ot vachamishim, literally six hundreds of thousands and three thousands and five hundreds and fifty, for 603,550. They tended to split the number up, ordered in terms of hundreds, with higher orders said before lower orders, just as in English; but, within each order-group, hundreds will be said first, then ones, and then tens.