Welcome to DU! The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards. Join the community: Create a free account Support DU (and get rid of ads!): Become a Star Member Latest Breaking News Editorials & Other Articles General Discussion The DU Lounge All Forums Issue Forums Culture Forums Alliance Forums Region Forums Support Forums Help & Search

The DU Lounge

rurallib

(64,794 posts) Sun Apr 12, 2026, 02:20 PM Apr 12

How did Romans manipulate numbers with their numeral system? [View all]

you know - add, subtract, multiply and divide? For some reason this floated into my brain the other day and now it is kind of haunting me.

There must have some way they could do it - after all they built viaducts and coliseums and homes and buildings. So they must have been able to add etcetera.

But let's just do a simple multiplication to illustrate how difficult it must have been: 7 times 14 = 98 or in Roman numerals:
VII times XIV = XCVIII (I think I got that right).

Trying to do math in your head with Roman numerals can really give you a headache.

10 replies

= new reply since forum marked as read

Highlight:

How did Romans manipulate numbers with their numeral system? [View all] rurallib Apr 12 OP

They used a portable abacus or counting boards. Irish_Dem Apr 12 #1

so they were actually using a base 10 system? rurallib Apr 12 #3

Yes, the abacus was a hand held calculator using a decimal (10 base) system. Irish_Dem Apr 12 #6

Not too complicated. My fifth or sixth grade class Ilsa Apr 12 #5

Well... underpants Apr 12 #2

such a useful meme. nt BootinUp Apr 12 #7

I was being ironic and sarcastic but, yes, it is very useful underpants Apr 12 #10

I didn't know it could be done. surfered Apr 12 #4

There are eleven types of people in the world Abnredleg Apr 12 #8

... rurallib Apr 12 #9