Can you read Roman Numerals? Roman Numbers? In Ancient Rome, they wrote their numbers
using CAPITAL LETTERS {weird, huh, reaction}. We still use Roman Numerals today, on our
clocks and watches… We use them to talk about big events, like the SUPER BOWL, or
the OLYMPICS!
But because we don’t use Roman Numerals all the time, it’s easy to get them mixed
up. There are 7 different letters used in Roman Numerals. Let’s think of ways to tell
which Roman Numeral is which!
The letter I stands for the number 1. That one’s easy, it looks like the number 1!
The letter V stands for the number 5. You can do a hand trick to remember this one {- hold
up one hand, and fold middle 3 fingers up-and-down, saying} V-5.V-5
The letter X stands for the number 10. You can remember this ‘cause you can take 2
Vs and make an X {animate this}. The letter L stands for the numer 50. ..I
don’t have a trick to remember that one. The letter C stands for the number 100. Like
how there are 100 cents in a dollar, or 100 years in a century!
The letter D stands for 500. .. Hmm..I don’t have a trick for that one either.
The letter M stands for 1000. This one’s easy if you speak French, because the word
for 1000 in French is mille. Like how there are 1000 years in a millenium.
Okay, we thought of SOME ways to remember these Roman Numerals, but it’d be nice to
have something for all the numbers. ... I KNOW! Let’s make up a sentence to help us
remember ALL these Roman numerals in order.
“I Value X-rays” - that’s the first 3 Roman Numerals in order. I ..V ...X stands
for 1..5...and 10.
“Let’s Count the Doctor’s Money.” I don’t know if the doctor’s gonna like
that, but it’ll help us remember the next 4 Roman Numerals in order. L...C...D...M..
stands for 50….100...500...and 1000.
There’s one more important thing to remember. There are only 7 Roman Numerals, so how do
you get more than those 7 numbers? You put them together in groups. So I is 1, II is
2, III is 3. But here’s the tricky part. You can’t put more than 3 of the same Roman
Numerals together in a group. So to get to the number 4, you can’t write IIII. Instead,
you write it like this: IV. That means take 1 away from 5, to get 4.
Do you know what VIII means? 5 + 1 + 1 + 1 = 8. But how do you write 9? You can’t write
VIIII, because that has more than 3 of something in a row. Instead, you write IX. That means
- take 1 away from 10, to get 9.
What’s this number? XX. That’s 10 + 10 = 20. XXX? 10+10+10 = 30. But how do you write
40? ...It’s not XXXX…{dramatic pause} ...it’s XL. Take 10 away from 50, to get
40.
The same goes for bigger numbers. 60 is LX. 70 is LXX. 80 is LXXX. But for 90 - you can’t
write LXXXX, you have to write...XC! 10 less than 100.
How about a REALLY big number? A lot of times, people write YEARS in Roman Numerals. Have
you seen that before? Like on important statues, or at the end of movies. How about the year
1969, the year the first people walked on the moon? How would we write 1 thousand, nine
hundred sixty nine?
First let’s break it up into smaller pieces. Remember 1969 is the same as 1000+900+60+9.
1 thousand is M.. 900 is 100 less than 1000, so we write that
part as CM.. 60 is 50 + 10 so we write that as LX..
9 is 1 less than 10, which is IX.. Let’s put that all together: M... CM...
LX... IX. That was a good year!
I for one love Roman numerals…. Get it?... I for one?...