# A little number riddle

Try your best to solve the puzzle below GOOD LUCK!!!

Explain why

1=0
2=0
3=0
4=0
10=0

And

7=1
8=1
9=1

But

5=2
6=2
11=2
12=2


The number of letters used in Roman numerals in the spelling of the number

Taken from dictionary.com: The Roman numeral system uses only seven symbols: I, V, X, L, C, D, and M. I represents the number 1, V represents 5, X is 10, L is 50, C is 100, D is 500, and M is 1,000. Different arrangements of these seven symbols represent different numbers.
Thus:

ONE 0 letters used in Roman numerals
TWO 0 letters
THREE 0 letters
FOUR 0 letters
TEN 0 letters

SEVEN 1 letter: V
EIGHT 1 letter: I
NINE 1 letter: I

FIVE 2 letters: IV
SIX 2 letters: IX
ELEVEN 2 letters: LV
TWELVE 2 letters: LV

• I've been staring at this for 15 solid minutes and you just blew my mind. Thank you. Jan 25 at 19:01
• @ConnieMnemonic The lateral-thinking tag kinda give it off as a non-math problem, and I thought if it's not math it had to be English or some word play. Anyways, you're welcome ;) Jan 25 at 19:03