# How to Denote 4 and 9 in Roman Numerals

The numbers 4 and 9 are some of the most complicated in Roman Numerals because they don't follow the same pattern as 1 through 3 or 6 through 8. Once you know the trick, it's easy!

## Steps

- 1
**Know your basic Roman Numeral symbols.**I=1, V=5, X=10, L=50, C=100, D=500, M=1000- For these symbols, I, X, C, M, they can only be repeated a maximum of three times only.
- Example: III, XXX, CCC, MMM
- There is no VVV, LLL and DDD

- 2
**Learn the basic structure for repeated symbols (which doesn't work for 4 and 9).**If you put something after V, X, L, C, D, M, that means to add the values together.*Remember that any symbol can only be repeated three times.*- I=1
- II=1+1
- III=1+1+1
- IIII...I+1+1+1+1...Nope!
- VI=5+1
- VII=5+1+1
- VIII=5+1+1+1 (symbol repeated three times max)
- VIIII=5+1+1+1+1...Nope!
- XI=10+1
- XII=10+1+1
- XIII=10+1+1+1
- XIIII=10+1+1+1+1...Nope!
- LI=50+1
- LII=50+1+1
- LIII=50+1+1+1 (symbol repeated three times max)
- LIIII=L+1+1+1+1...Nope!
- CI=100+1
- CII=100+1+1
- CIII=100+1+1+1
- CIIII=C+1+1+1+1...Nope!
- DI=500+1
- DII=500+1+1
- DIII=500+1+1+1 (symbol repeated three times max)
- DIIII=D+1+1+1+1...Nope!
- MI=M+1
- MII=M+1+1
- MIII=M+1+1+1
- MIIII=M+1+1+1+1...Nope!

- 3
**For Roman numerals that end in 4 or 9, you need to put an I before V, L, C, D, M, X.**This means "to subtract" instead of "to add." For this lesson, we are learning only "V" and "X".*Remember that any symbol can only be repeated three times.*- Then, what about 4? Is it IIII? No. Since V = 5, you put "I" before "V" to get the value of 4. So, it becomes,
- IV=5-1=4
- XIV =10+4=14
- XXIV=20+4=24
- XXXIV=30+4=34

- Then, what about 9? Is it VIIII? No. Since X = 10, you put "I" before "X" to get the value of 9. So, it becomes,
- IX =10-1=9
- XIX=10+9=19
- XXIX=20+9=29
- XXXIX=30+9=39

- Then, what about 4? Is it IIII? No. Since V = 5, you put "I" before "V" to get the value of 4. So, it becomes,

## Tips

- Also note that there are no zero's (0's) in the Roman Numeral system.

## Article Info

Categories: Mathematics