Why do they call a 100 dollar bill a C note?

Question

Just wondering?

Answer 1

century note, 100

Answer 2

Yes, C is the Roman Numeral equaling 100. A century is 100 years. A cent is 1/100 of a dollar. A centennial is a 100 year anniversary and so on, thus a C note = $100.  

Answer 3

The roman number C is equal to 100.  X is 10, M is 1000.