Reading Roman Numerals Everywhere

Roman numerals are all around you. They number the hours on many clocks, the chapters in books, the kings and queens (like Henry VIII or Elizabeth II), and the year a film was made.

To read a longer numeral, work left to right and keep a running total. Add each letter — but if a smaller letter comes before a bigger one, subtract it instead. Take XXVII: X + X + V + I + I = 10 + 10 + 5 + 1 + 1 = 27.

You did it! With just seven letters and two rules — add, and subtract when a small letter comes first — you can read numbers that are two thousand years old.