99 Fun Facts About Roman Numerals

Why was the NFL's 2016 title game branded Super Bowl 50 rather than Super Bowl L?

An L-only logo looked bad: the NFL's head of brand said the letter 'isn't as pleasing to the eye', a worry her designers had carried ever since drawing the logo for Super Bowl XL.

Which famous clock, its dials designed in 1852, writes four as IV rather than the IIII most clock faces use?

Big Ben, whose dial was designed in 1852, runs I to XII with a subtractive IV, while most Roman-numeral clock faces keep the older IIII for four yet still write nine as IX.

Roman fractions were counted in unciae, twelfths whose Latin name gave English which pair of units?

Inch and ounce both descend from uncia, the Roman twelfth: the Roman inch was a twelfth of a foot, and the Roman ounce a twelfth of a pound.

Which number does the Roman numeral MIX stand for, a numeral that happens to spell an English word?

1,009 is M plus IX with nothing written for the empty hundreds and tens: the Roman system has no zero symbol, so a missing place is simply left out, as in 207 written CCVII.

Roman numerals descend directly from the number symbols of which people, Rome's early neighbours and rivals?

Etruscans supplied the signs for 1, 5, 10, 50 and 100, which were not letters at first: the sign for 50 only settled into an L around the time of Augustus.

Which subtitle number did the original 1977 Star Wars gain on its 1981 re-release?

Episode IV was added in 1981 because the 1980 sequel had opened as Episode V, revealing George Lucas's plan for a longer saga in which the first film released sat in the middle.

Why did a film's title-screen year matter so much in Hollywood before 1989?

A wrong numeral could void copyright under US law until the Berne Convention Implementation Act of 1988 took effect, and even a smaller slip could change the date the copyright ran out.

Why is 49 written XLIX in standard Roman numerals, and never the two-letter IL?

I precedes only V or X, so the six standard subtractive pairs are IV, IX, XL, XC, CD and CM; 49 therefore has to be 40 plus 9, and 99 is XCIX rather than IC.

When a formal document dates itself 10.XI.1988, what does the Roman numeral XI stand for?

November is XI, the eleventh of the twelve: the mixed style writes that part of the date in Roman numerals and the day in Arabic ones, so 4.VI.1789 and VI.4.1789 both unambiguously mean 4 June 1789.

The Statue of Liberty's tablet reads JULY IV followed by which Roman numeral for the year 1776?

MDCCLXXVI is M + DCC + LXX + VI; the sculptor Bartholdi chose the date of the Declaration of Independence for the tablet to tie that day to the idea of liberty.

After the one-off Super Bowl 50, which Roman numeral did the NFL use for the next season's championship game?

LI, for 51, brought the numerals straight back, and the game earned its place in the record books: New England erased a 28-3 deficit to win the first Super Bowl decided in overtime.

On a Lithuanian shop's opening-hours sign written in Roman numerals, which day of the week does VII stand for?

Sunday is VII because such signs, also seen in railway and bus timetables, take Monday as the first day of the week and number it I.

Which Roman numeral spells 1066 in standard form, with the empty hundreds place simply omitted?

MLXVI is M + LX + VI: with no zero to mark it, the empty hundreds place goes unwritten, and swapping two letters gives 1046 (MXLVI) or 1064 (MLXIV) instead.

In IUPAC names for inorganic compounds, a Roman numeral in parentheses after a metal tells a chemist what?

Its oxidation number is what the numeral states, used for cations that can carry several different positive charges; chemists once numbered periodic-table groups the same way, a habit now officially deprecated.

On a graph that includes negative numbers, which Roman-numeral region has negative values on both axes?

Quadrant III is where both coordinates are negative: the four are numbered anticlockwise from the top right, so II has only a negative x and IV only a negative y.

A film made in 2026 would show which Roman numeral for its production year, with MM standing for 2000?

MMXXVI is MM + XX + VI: every year of this century opens with MM, which keeps the numerals shorter than in the 1900s, when each one had to begin MCM.

Which year is written MCMXCIX in Roman numerals?

1999 is M + CM + XC + IX, three subtractive pairs in a row; MCM alone signifies 1000 + 1000 − 100 = 1900, so every year of the 1900s opens with those same three letters.

Spanish writes 'siglo XVIII' and French 'XVIIIe siècle' to name which century?

The 18th century is XVIII, 10 + 5 + 3; Romance languages favour Roman numerals for centuries, as do Russian and Polish, while German and Turkish write '18.' with a full stop instead.

In a printed book, which part is conventionally page-numbered in lowercase Roman numerals such as iv and xii?

The preface and the rest of the front matter take lowercase numerals so that the main text can still begin on page 1; plays use them too, as in Act iii, Scene 2.

In the United States, what kind of suffix is the IV in a name such as William Howard Taft IV?

Generational suffixes follow a custom: Jr. is for a son who shares his father's full name, while II, read 'the second', usually marks a boy named after a grandfather or an uncle.

What does a vinculum, the bar drawn above a Roman numeral, do to the value written beneath it?

Multiplies it by 1,000: the bar came into use in the late Republic and was the common way to write thousands in the Imperial era, since M for 1,000 only arrived in the medieval period.

Which principle underlies Roman numerals such as XXVII, unlike the place-value system of Arabic digits?

Additive is the principle: XXVII is just 10 + 10 + 5 + 1 + 1, with no place value, which made written sums so awkward that accounts kept in Roman numerals were worked on an abacus.

The NFL first put a Roman numeral on its championship game in January 1971; which edition was that?

V was the first to carry a numeral, and the four earlier games were numbered in hindsight; a number suits a game that is played in the calendar year after its season.

Which English cathedral's late-1300s clock already showed IIII for four, as most Roman-numeral dials still do?

Wells Cathedral's clock still sends a set of jousting knights charging round every quarter of an hour, and its medieval dial pairs IIII with a subtractive IX.

How did the builders of Rome's Colosseum label entrance 44, shunning IV while using XL for forty?

XLIIII is carved over gate 44 because the Colosseum's masons wrote XL but avoided IV; the numbers matched those on spectators' pottery tickets and steered each to the right arch.

Which Latin word did Dionysius Exiguus write for zero alongside Roman numerals in a 525 manuscript?

Nulla stood in for zero in a 525 table by Dionysius Exiguus; around 725 Bede or a colleague wrote just the letter N instead, a habit apothecaries kept up on prescriptions into the 20th century.

The Roman symbol for 1,000 drifted from a circled X to the letter M under the influence of which Latin word?

Mille, Latin for 'thousand', pulled the symbol toward M; before that the 1,000 sign was partly identified with the Greek letter phi and passed through shapes resembling Ψ and ∞.

France's Sun King, the fourteenth Louis, seems to have preferred which form of his number on coins?

XIIII is how the Sun King's gold coins number him, in the legend LVD XIIII; William IV of Great Britain and Charles IV of Spain likewise had IIII struck on their coinage.

Roman numerals on the stern of the clipper Cutty Sark, rising from 13 to 22, mark what in feet?

Draught marks show how deep the hull sits, which changes with the load, so a glance told the crew how heavily laden she was; the Cutty Sark's climb the stern from 13 feet to 22.

A Renaissance chronogram hid what inside a phrase by counting the letters I, V, X, L, C, D and M?

A year was the usual payload, since chronograms marked tombstones and foundation stones: 'My Day Closed Is In Immortality' hides MDCIII, 1603, the year Elizabeth I died.

The French Revolutionary calendar counted Year I from which event?

The Republic's founding in September 1792 opened Year I, yet the calendar itself was adopted only in October 1793 and backdated, and it was dropped in Year XIV.

In old apothecaries' prescriptions, what did SS mean after a quantity?

One half is SS, from the Latin semis: the Roman fraction S turned VIIS into seven and a half on ancient inscriptions, and it stood for six twelfths rather than five tenths.

Which Italian mathematician's 1202 book Liber Abaci championed the Hindu-Arabic numerals that slowly displaced Roman ones?

Fibonacci learned the new digits as a boy in Bugia, in modern Algeria, where his father was a customs official, yet merchants' accounts kept Roman numerals into the 1400s.

In entomology, the broods of which insects are identified by Roman numerals, as in Brood X?

Periodical cicadas got their numerals from the entomologist Charles Marlatt, who numbered thirty possible broods on 13- and 17-year cycles; only fifteen are known to exist.

Astronomers label a planet's moons with Roman numerals after its name; which moon is Saturn VI?

Titan is Saturn VI even though it was the first of the planet's moons to be found, in 1655: the first numerals were given in order of distance from Saturn, and moons I to V orbit closer in.

London 2012 was officially the Games of which Olympiad, written in Roman numerals?

XXX is 30 because Olympiads are counted even when no Games take place: the three editions lost to the world wars kept their numbers, so London 2012 was only the 27th Summer Games held.

Which year appears as MDCCCLXXXVIII on the façade of the Cambridge Public Library in Massachusetts?

1888 is M + DCCC + LXXX + VIII; the library went up that year on land given by Frederick Rindge, a Cambridge-born philanthropist who also paid for the whole building.

Which numeral writes 2,421 in standard Roman numerals?

MMCDXXI is MM + CD + XX + I: 400 is CD, a hundred taken from five hundred, and the longhand MMCCCCXXI counts as a variant rather than the standard form.

The Colosseum's surviving numbered entrances run from XXIII up to LIIII; what number is that highest gate?

54 is LIIII in the plain-stroke style the carvers used for units, proof that the classical form was largely settled by the time the arena was completed in AD 80, even if IV was shunned.

A three-sided box drawn around a Roman numeral, an extension of the vinculum, raises its value by what factor?

100,000 is the box's factor, so a boxed XIII meant 1,300,000, which let Roman writers set down the huge totals of paces in their geographies without endless strings of letters.

London's Admiralty Arch gives its 1910 date with a variant, non-subtractive 900; how does it read?

MDCCCCX uses DCCCC where MCM is standard; the Latin inscription dates the arch to the tenth year of Edward VII, who commissioned it but did not live to see it finished.

The 1954 film The Last Time I Saw Paris wrongly dated itself MCMXLIV on screen; which year does that numeral give?

1944 is how MCMXLIV reads, a full decade early and earlier even than the end-of-war celebrations in Paris with which the story opens; the correct numeral was MCMLIV.

Unicode gives every Roman numeral from 1 up to which number its own single character, handy in vertical Asian text?

12 is where the unbroken run of single characters stops; Unicode keeps them only for compatibility with East Asian standards and advises composing numerals from ordinary Latin letters instead.

French texts from the 15th century wrote 99 as IIII·XX·XIX, mirroring which spoken French number phrase?

Quatre-vingt-dix-neuf is 'four twenties and nineteen', exactly IIII·XX plus XIX; the same counting by twenties names Paris's Quinze-Vingts hospital, founded with 300 beds for the blind.

Without the letter M, what is the largest number that standard-form Roman numerals can write?

899 is DCCCXCIX: the next number, 900, is written CM in standard form and so needs an M, which puts 999 out of reach as well.

Which number below 4,000 needs the most letters, fifteen, when written in standard Roman numerals?

3,888 is MMMDCCCLXXXVIII, every place sitting at its eight; the far larger 3,999 takes only nine letters because each 9 collapses into a two-letter subtractive pair.

Lower-case Roman numerals like iv only became possible once minuscule letters were developed in which era?

The Middle Ages gave Europe its lower-case letters, notably the Carolingian minuscule fostered under Charlemagne; since then a final i has often been written j, as in vij for 7.

In seismology, which earthquake intensity scale expresses its degrees in Roman numerals?

Mercalli intensities describe the shaking felt at one place rather than the energy released, so a single earthquake has one magnitude but many Roman-numeral intensities.

The Greek Old Testament is nicknamed LXX after the legendary number of its translators; which number is that?

70 is LXX, from the Latin septuaginta, 'seventy', though the legend itself counts seventy-two translators, six from each of the twelve tribes of Israel.

Which year, when the Great Fire of London broke out, is written MDCLXVI, each Roman symbol once in descending order?

1666 lines up all seven symbols, M D C L X V I, with none repeated. The fire began on 2 September and destroyed much of the English capital over the next four days.

Apple's 2017 iPhone X took the Roman numeral in its name from which anniversary of the original iPhone?

The tenth anniversary gave the phone its X, and Apple skipped an iPhone 9 to get there. It was also the first iPhone designed without a home button.

Which American rock band, named after a city, became known for titling its albums with sequential Roman numerals?

Chicago shortened its name from Chicago Transit Authority after its first album and went on to number its records like volumes. The numerals and a recognisable emblem on every cover made the band a pioneer of rock marketing.

The Rise of Skywalker closed the Skywalker saga in 2019 as Star Wars Episode IX: which episode number is that?

It is episode 9, the closing chapter of the nine-part Skywalker saga. The I standing before the X is taken away from it, leaving one less than the X alone.

Enigma's debut album, which mixed Gregorian chant with dance beats, is titled MCMXC a.D. after which year?

1990 is the year the album came out, and it had sold twelve million copies worldwide within four years. Its sampled chant also brought a lawsuit from the record label of a Munich choir.

A club's top side is often called the '1st XV' in which sport, the Roman numeral counting its players?

Rugby union sends fifteen players a side onto the field, eight forwards and seven backs. That is two more forwards than a rugby league side has.

In most traditional tarot decks, which Major Arcana card carries the Roman numeral XIII?

Death is the 13th trump, and readers say it seldom stands for a physical death. It more often points to an ending, such as the close of a relationship or an interest.

The Titanic sank on its maiden voyage in 1912: which of these Roman numerals correctly writes that year?

MCMXII marks the year the liner went down on 15 April, one of history's deadliest maritime disasters. The First Balkan War broke out in October of the same year.

One theory holds that Romans avoided writing IV because it began the Latin spelling of which god's name?

Jupiter was spelled IVPITER in Latin capitals, so IV might have seemed an impious way to write a number. Isaac Asimov passed the idea on as an interesting theory without saying whose it was.

A common year has 365 days: which of these Roman numerals correctly writes that number?

CCCLXV is three hundreds, a fifty, a ten and a five, written largest first. A leap year's extra day simply adds a single I to the end.

Columbus reached the Americas in 1492, a year whose Roman numeral subtracts twice: which of these is it?

MCDXCII uses the subtractive rule for both its hundreds and its tens. Columbus arrived from Spain that October, under terms the Spanish crown had agreed with him only in April.

Apollo 11 put the first humans on the Moon in 1969: how is that year written in Roman numerals?

MCMLXIX was the year Neil Armstrong and Buzz Aldrin walked on the lunar surface, on 20 July. Woodstock drew a crowd of over 400,000 a few weeks later.

King John agreed to Magna Carta at Runnymede in 1215: which Roman numeral writes that year?

MCCXV needs only five letters, because nothing in the date calls for subtraction. The pope annulled the charter that August, freeing the king from its limits.

Odoacer deposed Romulus Augustulus in 476, the traditional fall of Western Rome: how do Roman numerals write 476?

CDLXXVI was the year Romulus Augustulus lost his throne at Ravenna, on 4 September. Historians have long used the date to mark where the ancient world gives way to the medieval one.

Mount Vesuvius destroyed Pompeii and Herculaneum in AD 79: which of these Roman numerals stands for 79?

LXXIX is the number, though Romans of the day named the year after its consuls, Titus and Vespasian. The eruption also wiped out the towns of Stabiae and Oplontis.

The Second World War ended in 1945 with the defeat of Germany and Japan: how is that year written in Roman numerals?

MCMXLV puts its X before the L, and writing the pair the other way round moves the date on by twenty years. The war's end left the world with two superpowers, the United States and the USSR.

Some historical documents shortened 99 to IC, but which is the standard Roman numeral for that number?

XCIX is the standard form, written tens first and then units. The shortcut may echo spoken Latin, where the number was undecentum, literally 'one from a hundred'.

Parisians stormed the Bastille in 1789: which of these long Roman numerals correctly writes that year?

MDCCLXXXIX takes ten letters, and the crowd that took the fortress on 14 July found only seven prisoners inside to free.

Ray Bradbury's Fahrenheit 451 is named for the temperature at which paper burns: how do Roman numerals write 451?

CDLI spells the number in just four letters. Bradbury settled on the figure after asking at what temperature paper would catch fire, and being told 451 °F.

The Boeing 747 was the first airliner called a Jumbo Jet: which Roman numeral writes its model number?

DCCXLVII is the 747, also nicknamed Queen of the Skies. The other three numerals spell out its Boeing stablemates, the 737, 767 and 777.

MMMCMXCIX is the largest number that standard Roman numerals can write without extra marks: what is it?

3,999 is the ceiling because the standard symbols end at M, which is written no more than three times in a row. Anything bigger needed extra devices, and writers tried several over the centuries.

Super Bowl XLII, in which the Giants upset the heavily favoured Patriots, carried which number in ordinary digits?

Number 42 produced one of the biggest upsets in North American sport, a 17–14 Giants win. Its best-remembered play was David Tyree's leaping catch, pinned against the crown of his helmet.

Amendment XIX to the US Constitution barred denying the vote on account of sex in 1920: which amendment number is that?

Amendment 19 took effect in August 1920, when Tennessee became the last state needed. Its House had approved the measure narrowly, with 50 of its 99 members voting yes.

The Roman numeral CD shares its two letters with the compact disc: which number does it stand for?

400 is a hundred taken from five hundred, because the smaller letter comes first. Write the same two letters the other way round and they add up to 600 instead.

The letters MD follow an American physician's name, but which number do they make as a Roman numeral?

1,500 is simply a thousand followed by five hundred, with nothing subtracted. The year that carried the numeral was the last of the fifteenth century.

CM is one of six subtractive pairs in standard Roman numerals and the largest in value: what is it worth?

900 is a hundred taken from a thousand, the biggest subtraction the standard system allows. The only other pairs of the kind are IV, IX, XL, XC and CD.

A standard modern piano has LXXXVIII keys, written here in Roman numerals: how many keys is that?

88 keys is the modern standard, split into 52 white and 36 black. Together they span a little over seven octaves.

Joseph Ratzinger reigned as Pope Benedict XVI until resigning in 2013: which number is XVI?

XVI is 16, built from a ten, a five and a one in descending order. Benedict was the first pope to resign since 1415, and the first to go without outside pressure since 1294.

The Saint Louis Art Museum, built for the 1904 World's Fair, is inscribed MDCDIII: which year did its carvers mean?

1903 is the reading, although the usual numeral for that year looks quite different. The engraving was part of the original building designed for the fair.

Which Japanese role-playing series, launched in 1987, numbers its core games in Roman numerals, reaching XVI in 2023?

Final Fantasy got its title, creator Hironobu Sakaguchi once said, from his feeling that the game was his last-ditch effort in the industry. He later added that the team simply wanted a name that shortened to FF.

With its second crewed flight, in June 1965, which NASA program switched to Roman numerals for mission names?

Gemini made the change on the flight that saw Ed White become the first American to float outside a spacecraft. The four-day mission was also the first run from the new Mission Control Center in Houston.

Anatomists number the cranial nerves in Roman numerals: which one, serving the heart, lungs and gut, is nerve X?

The vagus nerve drives the body's 'rest and digest' response, calming things down after stress and lowering the heart rate. It carries both sensory and motor fibres.

In the Sun's spectral type, G2V, the Roman numeral V places it in which luminosity class of stars?

Main sequence stars such as the Sun carry a V, while the scale opens at I for supergiants. Astronomers at Yerkes Observatory introduced the scheme in 1943.

In the Roman numeral analysis of music, what kind of chord do lowercase numerals such as ii and vi usually mark?

Minor chords take lowercase numerals in the most common convention, with capitals reserved for major ones. Some theorists prefer capitals for every chord, whatever its quality.

Scientists label the crystalline phases of which everyday substance with Roman numerals such as Ih, VII and XV?

Ice of the everyday kind is the hexagonal phase, Ih, which accounts for most of the frozen water on Earth. More than twenty crystalline phases have been observed in all.

Which American photographer co-devised the Zone System, which labels tones with Roman numerals from 0 to X?

Ansel Adams formulated the system with Fred Archer, running from Zone 0 for pure black up to Zone X for white. Each step along the scale doubles the exposure of the one before.

Why did old medical prescriptions often end a lowercase Roman numeral with j, writing iij for three?

To stop tampering or misreading once a number was written, doctors closed it with a j. The letter began as a flourished form of i, and the habit lasted into the early twentieth century.

John Wallis introduced which symbol in 1655, one conjectured to derive from a Roman numeral for a thousand?

The infinity sign may echo a rounded Roman mark for a thousand, a number also used loosely to mean 'a great many'. Wallis never explained his choice, and a rival theory points to the Greek letter omega.

The Roman numeral D may have begun as which part of an older symbol for a thousand, twice its value?

The right portion, an I closed by a backwards C, may have come to be read as the letter D. On one scholar's account V arose the same way, as an X cut in two.

Excel's ROMAN function offers a 'more concise' mode: which two-letter form can it give for 499, normally CDXCIX?

ID takes one from five hundred, a shortcut outside the standard rules. Microsoft's help page offers no reason for the looser forms beyond calling them 'more concise'.

A 1301 account wrote one total as XIII·M·V·C·III·XX·XIII, multiplying as it went: which number is that?

13,573 is thirteen thousands, five hundreds, three score and thirteen. The clerk set each multiplier in front of its unit, much as the words would be spoken aloud.

Scotland's 'Pillar Box War' of the 1950s targeted post boxes bearing which Roman numeral in the new Queen's cypher?

II angered some Scots because the first Elizabeth had never reigned over Scotland. After vandalism and even explosions, new Scottish boxes carried only the Crown of Scotland.

Varro dated Rome's founding to 753 BC, the basis of the AUC calendar: how do Roman numerals write 753?

DCCLIII is the number on which the Roman year count rests. Despite known errors in Varro's sums, his date remains the usual starting point for the era.

George Orwell's Nineteen Eighty-Four is often printed as 1984: which Roman numeral writes that number?

MCMLXXXIV is the year of the title, though the novel itself came out in June 1949. It was Orwell's ninth completed book, and the last he finished.

Which year, when Paris hosted the Summer Olympics, is written MMXXIV in Roman numerals?

2024 takes only six letters, because every year of this century opens with a plain MM. It was a leap year that began on a Monday.

A maximum break in snooker scores 147 points: which Roman numeral writes that total?

CXLVII is snooker's perfect score, first officially recognised when Joe Davis made one in a 1955 exhibition match in London.

Levi's gave its copper-riveted jeans the lot number 501 in 1890: which Roman numeral writes 501?

DI is all it takes: five hundred and then one. The company started giving its products lot numbers in the same year that its rivet patent ran out.

In the Rider–Waite tarot, whose trumps carry Roman numerals, which card is numbered with an Arabic 0 instead?

The Fool gets the 0 because Roman numerals have no symbol for nothing. In most decks made before this one, the card carried no number at all.

The Armistice that ended the fighting of World War I came in 1918: how is that year written in Roman numerals?

MCMXVIII was also the first year of the Spanish flu pandemic, which killed an estimated 50 million people worldwide.

Dodie Smith's 1956 children's novel counts 101 Dalmatians: which Roman numeral writes that number?

CI is a hundred and one in just two letters. The story was first serialised as The Great Dog Robbery, and follows Pongo and Missis as they rescue their puppies from a fur farm.