Hebrew Mathematics

Date: 09/21/2000 at 15:50:12
From: Jared Lursen
Subject: Hebrew Mathematics

Help, Dr. Math -

I need to write a one-page article on the Hebrew Mathematics system, 
and also show how the numbers 1-10, 25, and 100 are written in Hebrew.  
We've searched on the Internet and in encyclopedias and still can't 
find what we need.

Thanks for your help.

Jared

Date: 09/26/2000 at 09:23:30
From: Doctor Wolfson
Subject: Re: Hebrew Mathematics

Hi Jared,

Here's a pointer to a Web page that lists the Hebrew numbers:

  Learn the Aleph-Bet - Akhlah: The Jewish Children's Learning Network
  http://www.akhlah.com/Aleph_Bet/aleph-bet.asp   

In Hebrew, there is no difference between the symbols for numbers and 
the ones for letters. Each of the 22 main letters of the Hebrew 
alphabet also represents a number, as this page shows. The numbers are 
assigned to letters in a way that you can always combine the right 
letters to get a number you want. 

To begin with, the first letter, Aleph, has the value 1. 
The next letter, Bet, has the value 2, and so on up to Yud=10. After 
that, each letter is an increment of ten, so that Kaf=20 and so on, 
until Qof (usually pronounced like "cough")=100. The last three 
letters increase in value by 100, so Resh = 200, Shin = 300, and 
Tav = 400.

Well, you will usually be talking about a number that doesn't happen 
to be one of these 22, so there has to be a way to combine them to 
form new numbers. Sure enough, to combine several numbers, you just 
write them next to each other, in descending order. That means that 
the highest number comes first. But since in Hebrew, "first" means "at 
the right," you would write them with the highest numbers at the 
right. 

So let's say I want to write out the number 965. Well, there is no 
900. In fact, there isn't anything bigger than 400. So I need to use a 
400, a 300, and a 200 to get 900. That's Tav, Shin, and Resh. For 60, 
I need Samech, and for 5 I need Hey. So if you saw it written out, it 
would look like this:

     (Hey)(Samech)(Resh)(Shin)(Tav)

or roughly,      

     H"sRST

Often, you'll see the double-quote mark inserted in a number, as I did 
above, to show that it's a number and not a word (just try to 
pronounce that!) :-)

Numbers are grouped by thousands just as we use commas to write 
1,045,645. So to write 5760, you would write (60)(300)(400)(5) or 
Vav-Shin-Tav-Hey

I hope this is a good start for you. Feel free to write back if you'd 
like me to clarify this more.

- Doctor Wolfson, The Math Forum
  http://mathforum.org/dr.math/