As you can see these are Roman Numerals. Not all numbers start with X of course, and there are certain rules about the use of the numbers so that the X can mean 10 less than the next number letter - does that make sense?
We have all seen Roman Numerals about, most commonly on clocks, but also on door numbers and tombstones among others. They are a very efficient numeral way to write numbers but went out of fashion when we began using the Hindu-Arabic numerals in the 14th century which you can see on your keyboard right now. One big difference between the two systems is that although they were also decimal the Roman Numerology did not have a number for zero which is quite odd to think about now, I'm not sure how they got around that in general but some ancients used Nulla meaning None.
There are a few rules for using Roman Numerals, the first being that the subtractive numbers on the left should only be I, X or C but not the multiply by 'five' numbers, V, L and D. That number must be less than a 10th of the following letter, and only one letter is usually allowed to the left. This is why both The Chauffeur and I have an X before the L in our ages. I won't be too happy when I lose that X before the L and even less so when it moves to the right. I say there are rules but they are often disregarded and some numbers can be written ridiculously long, for instance my age could have been written XXXXVII which looks quite pretty, now I look at it.
Here are the number symbols with our modern number next to them to let you know what they all are in case you are unsure.
I = 1
V = 5
X = 10
L = 50
C = 100
D = 500
M = 1,000
So, can you work out our ages?
