Yep!!!
another 'techo' word. This time it just means to represent
some numbers in roman numerals you need to subtract the
value of the smaller number from the larger.
e.g.
XL = 50  10 = 40
Personally
I like the way it is shown on the chalk board but you'll
have to work out which way works for you.
Hint:
When smaller numerals are on the left of larger ones...
subtract.
When
you think you've got it, try these:

IV =
 IX
=
 CM =
 XC =
 CD =
Now
make up IV questions for
your friends to make sure they have mastered this concept.
Notable
Roman Numeral Quote
'Class, please! If you don't learn roman numerals, you'll
never know the date certain motion pictures were copyrighted.'
Edna
Krabappel (from The Simpsons)