Okay, this question popped into my mind as we approach the true Millenium Eve.
In this column, Cecil tackles the problem of the calendar in use when the Nazarene was born and how the present year-numbering system came into use. We also know that, at the time, the concept of “0” wasn’t known and therefore wasn’t included in the calendar, which is why the New Millenium starts on 01/01/2001.
My question is, if they didn’t have a zero number, how did they represent such numbers at 10, 20, 30, etc? Did they still use Roman numerals or some old notation that’s no longer in use?
In the Arabic system, you would see the infamous zero so posing the question to say some Roman plebian some 2000 years ago would be odd. However, you can say for example “2 fives” to represent “ten” in some strange numeric systems that don’t have a zero, although those Romans had the dope-ass “X” to represent that.
The Romans DID use two fives to represent ten- the X is two V’s, with one upside-down and another on top, so their vertices are touching.
Back to the OP- you only need a zero in your system if you use a base system like ours to make numbers (it doesn’t matter if you use base two, ten, etc.- you still need a zero). The Romans (and some others) didn’t use a base-style numbering system, and no zero was necessary.
A big advance in math came when we decided to assign values to where the number was placed. With place-value notation, you can do interesting things like convert to binary or hexadecimal (base 2 and 16, respectively) notation, simplify operations (would you rather add XXIV to VIII or 24 to 8?), and standardize notation (there was no ‘Received Notation’ for Roman Numerals, so you had to know a few main systems to figure out what you were looking at [for example, M could just as easily be (|), or a C, a line, and a reversed C]). In short, modern engineering and technology depends upon place-value notation (imagine trying to build a spacecraft with Xs and Vs).