Welcome to Super Bowl LIX. That's Super Bowl 59 for those untrained in Roman numerals, featuring the Kansas City Chiefs facing the Philadelphia Eagles at 6:30 p.m. Sunday in New Orleans.

Roman numerals are a numeral system which was used in Ancient Rome. It uses letters instead of numbers to represent values. You may have seen Roman numerals on clocks and on TV or film credits.

Some elements, particularly the transition metals, do not always have the same valency in their different compounds. The valency of these elements is usually given in roman numerals inside brackets.