Roman numerals from 1 to 15. How to make a date of birth from Roman numerals

We don't use Roman numerals often. And it seems that everyone knows that we traditionally use Roman numerals to denote centuries, and years and exact dates - with Arabic numerals. Just the other day I had to explain to Arab :-)) and Chinese students what, for example, XCIV or CCLXXVIII :-)) is. I learned a lot of interesting things for myself when I was looking for material. I’m sharing :-)) Maybe someone else will need it :-))

Roman numerals

Roman numerals are special characters used to record decimal places and their halves. To denote numbers, 7 letters of the Latin alphabet are used:

Roman Numeral Number

I 1
V 5
X 10
L 50
C 100
D 500
M 1000

Natural numbers are written by repeating these 7 Roman numerals.

Mnemonic rule for memorizing the letter designations of Roman numerals in descending order (the author of the rule is A. Kasperovich):

M s
D we eat
C tips
L look
X ok
V well-mannered
I to individuals

Rules for writing numbers in Roman numerals:

If a larger number comes before a smaller one, then they are added (addition principle),
- if a smaller number comes before a larger one, then the smaller one is subtracted from the larger one (subtraction principle).

The second rule is used to avoid repeating the same number four times. Thus, Roman numerals I, X, C are placed respectively before X, C, M to indicate 9, 90, 900 or before V, L, D to indicate 4, 40, 400.

VI = 5+1 = 6,
IV = 5 - 1 = 4 (instead of IIII),
XIX = 10 + 10 - 1 = 19 (instead of XVIIII),
XL = 50 - 10 =40 (instead of XXXX),
XXXIII = 10 + 10 + 10 + 1 + 1 + 1 = 33, etc.

It should be noted that performing even arithmetic operations on multi-digit numbers in this notation is very inconvenient. Probably, the complexity of calculations in the Roman numbering system, based on the use of Latin letters, was one of the compelling reasons for replacing it with a more convenient decimal system of numbers.

The Roman numbering system, which dominated Europe for two thousand years, is now in very limited use. Roman numerals are used to indicate centuries (XII century), months when indicating the date on monuments (21.V.1987), time on watch dials, ordinal numbers, derivatives of small orders.

Additional Information:

To correctly write large numbers in Roman numerals, you must first write the number of thousands, then hundreds, then tens, and finally units.

Example : number 1988. One thousand M, nine hundred CM, eighty LXXX, eight VIII. Let's write them down together: MCMLXXXVIII.

Quite often, to highlight numbers in the text, a line was drawn over them: LXIV. Sometimes a line was drawn both above and below: XXXII - in particular, this is how it is customary to highlight Roman numerals in Russian handwritten text (this is not used in typesetting due to technical complexity). For other authors, the overbar could indicate an increase in the value of the figure by 1000 times: VM = 6000.

Tissot watch with the traditional “IIII” spelling

Exists "shortcut" to write large numbers such as 1999. It Not recommended, but sometimes used for simplicity. The difference is that to reduce a digit, any digit can be written to the left of it:

999. Thousand (M), subtract 1 (I), we get 999 (IM) instead of CMXCIX. Consequence: 1999 - MIM instead of MCMXCIX
95. One hundred (C), subtract 5 (V), get 95 (VC) instead of XCV
1950: Thousand (M), subtract 50 (L), get 950 (LM). Consequence: 1950 - MLM instead of MCML

This method is widely used by Western film companies when writing the year of release of a film in the credits.

It was only in the 19th century that the number “four” was written down as “IV”; before that, the number “IIII” was most often used. However, the entry “IV” can already be found in the documents of the Forme of Cury manuscript dating back to 1390. Watch dials have traditionally used "IIII" instead of "IV" in most cases, mainly for aesthetic reasons: this spelling provides visual symmetry with the "VIII" numerals on the opposite side, and an inverted "IV" is more difficult to read than "IIII".

Another version.

There are seven basic numbers used to write integers in Roman numeration:

I = 1
V=5
X = 10
L=50
C=100
D = 500
M = 1000

In this case, some of the numbers (I, X, C, M) may repeat, but no more than three times, thus, they can be used to write any integer up to 3999 (MMMCMXCIX). When writing numbers in the Roman numeral system, the smaller digit may appear to the right of the larger one; in this case it is added to it. For example, the number 283 in Roman is written like this:

i.e. 200+50+30+3=283. Here the figure representing a hundred is repeated twice, and the figures representing ten and one, respectively, are repeated three times.

The smaller number can be written to the left of the larger one, then it should be subtracted from the larger one. In this case, repetitions of a smaller number are not allowed. Let's write the number 94 in Roman:

XCIV=100-10+5-1=94.

This is the so called "subtraction rule": it appeared in late antiquity (before that, the Romans wrote the number 4 as IIII, and the number 40 as XXXX). There are six ways to use the "subtraction rule":

IV = 4
IX = 9
XL=40
XC = 90
CD = 400
CM = 900

It should be noted that other methods of "subtraction" are not acceptable; thus, the number 99 should be written as XCIX, but not as IC. However, nowadays, in some cases, a simplified notation of Roman numerals is also used: for example, in Microsoft Excel, when converting Arabic numerals to Roman using the "ROMAN()" function, you can use several types of representation of numbers, from classical to highly simplified (for example, the number 499 can be written as CDXCIX, LDVLIV, XDIX, VDIV or ID).

From here it is clear that in order to avoid 4-fold repetition, the maximum possible number here is 3999, i.e. MMMIM

Large numbers can also be written using Roman numerals. To do this, a line is placed over those numbers that denote thousands, and a double line is placed over those numbers that denote millions. For example, the number 123123 would look like this:
_____
CXXIIICXXIII

And a million is like Ī, but with not one, but two features at the head.

Examples of writing numbers in Roman and Arabic numerals

Roman numerals Arabic numerals

I 1 unus
II 2 duo
III 3 tres
IV 4 quattuor
V 5 quinque
VI 6 sex
VII 7 september
VIII 8 octo
IX 9 November
X 10 December
XI 11 undecim
XII 12 duodecim
XIII 13 tredecim
XIV 14 quattuordecim
XV 15 quindecim
XVI 16 sedecim
XVII 17 september
XVIII 18 duodeviginti
XIX 19 undeviginti
XX 20 viginti
XXI 21 unus et viginti
XXX 30 triginta
XL 40 quadraginta
L 50 quinquaginta
LX 60 sexaginta
LXX 70 septuaginta
LXXX 80 octoginta
XC 90 nonaginta
C 100 centum
CC 200
CCC 300 trecenti
CD 400 quadringenti
D 500 quingenti
DC 600 sescenti
DCC 700 septingenti
DCCC 800 octingenti
CM 900 nongenti
M 1000 mille
MM 2000 duo milia
MMM 3000
MMMIM(largest number) 3999

Additional examples:

XXXI 31
XLVI 46
XCIX 99
DLXXXIII 583
DCCCLXXXVIII 888
MDCLXVIII 1668
MCMLXXXIX 1989
MMIX 2009
MMXI 2011

Roman numerals, invented more than 2,500 years ago, were used by Europeans for two millennia before being replaced by Arabic numerals. This happened because Roman numerals are quite difficult to write, and any arithmetic operations in the Roman system are much more difficult to perform than in the Arabic number system. Despite the fact that the Roman system is not often used today, this does not mean that it has become irrelevant. In most cases, centuries are denoted in Roman numerals, but years or exact dates are usually written in Arabic numerals.

Roman numerals are also used when writing the serial numbers of monarchs, encyclopedic volumes, and the valency of various chemical elements. The dials of watches also often use Roman numerals.

Roman numerals are certain signs with which decimal places and their halves are written. For this purpose, only seven capital letters of the Latin alphabet are used. The number 1 corresponds to the Roman numeral I, 5 – V, 10 – X, 50 – L, 100 – C, 500 – D, 1000 – M. When denoting natural numbers, these numbers are repeated. So 2 can be written using two times I, that is, 2 – II, 3 - three letters I, that is, 3 – III. If a smaller digit comes before a larger one, then the principle of subtraction is used (the smaller digit is subtracted from the larger one). So, the number 4 is depicted as IV (that is, 5-1).

In the case when a larger number comes in front of a smaller one, they are added, for example, 6 is written in the Roman system as VI (that is, 5+1).

If you are used to writing numbers in Arabic numerals, then some difficulties may arise when you need to write centuries in Roman numerals, a number or a date. You can convert any number from the Arabic system to the Roman number system and vice versa very easily and very quickly using the convenient converter on our website.

On your computer keyboard, just switch to English to easily write any number in Roman numerals.

Apparently, the ancient Romans preferred straight lines, which is why all their numbers are straight and strict. However, Roman numerals are nothing more than a simplified image of the fingers of a human hand. The numbers one to four resemble outstretched fingers, the number five can be compared to an open palm with the thumb protruding. And the number ten resembles two crossed hands. In European countries, when counting, it is customary to straighten your fingers, but in Russia, on the contrary, bend them.

We all use Roman numerals - we use them to mark the numbers of centuries or months of the year. Roman numerals are found on clock dials, including the chimes of the Spasskaya Tower. We use them, but we don't know much about them.

How do Roman numerals work?

The Roman counting system in its modern version consists of the following basic signs:

I 1
V 5
X 10
L 50
C 100
D 500
M 1000

To remember numbers that are unusual for us who use the Arabic system, there are several special mnemonic phrases in Russian and English:
We Give Juicy Lemons, That's Enough
We Give Advice Only to Well-Educated Individuals
I Value Xylophones Like Cows Dig Milk

The system for arranging these numbers relative to each other is as follows: numbers up to three inclusive are formed by adding units (II, III) - repeating any number four times is prohibited. To form numbers greater than three, the larger and smaller digits are added or subtracted, for subtraction the smaller digit is placed before the larger one, for addition - after, (4 = IV), the same logic applies to other digits (90 = XC). The order of thousands, hundreds, tens and units is the same as what we are used to.

It is important that any number should not be repeated more than three times, so the longest number up to a thousand is 888 = DCCCLXXXVIII (500+100+100+100+50+10+10+10+5+1+1+1).

Alternative options

The ban on the fourth use of the same number in a row began to appear only in the 19th century. Therefore, in ancient texts one can see variants IIII and VIII instead of IV and IX, and even IIII or XXXXXX instead of V and LX. Remnants of this writing can be seen on the clock, where four is often marked with four units. In old books, there are also frequent cases of double subtractions - XIIX or IIXX instead of the standard XVIII.

Also in the Middle Ages, a new Roman numeral appeared - zero, which was denoted by the letter N (from the Latin nulla, zero). Large numbers were marked with special signs: 1000 - ↀ (or C|Ɔ), 5000 – ↁ (or |Ɔ), 10000 – ↂ (or CC|ƆƆ). Millions are obtained by double underlining standard numbers. Fractions were also written in Roman numerals: ounces were marked using symbols - 1/12, half was marked with the symbol S, and everything greater than 6/12 was marked with an addition: S = 10\12. Another option is S::.

Origin

At the moment there is no single theory of the origin of Roman numerals. One of the most popular hypotheses is that Etruscan-Roman numerals originated from a counting system that uses notched strokes instead of numbers.

Thus, the number “I” is not the Latin or more ancient letter “i”, but a notch reminiscent of the shape of this letter. Every fifth notch was marked with a bevel - V, and the tenth was crossed out - X. The number 10 in this count looked like this: IIIIΛIIIIX.

It is thanks to this recording of numbers in a row that we owe a special system of adding Roman numerals: over time, the recording of the number 8 (IIIIΛIII) could be reduced to ΛIII, which convincingly demonstrates how the Roman counting system acquired its specificity. Gradually, the notches turned into graphic symbols I, V and X, and acquired independence. Later they began to be identified with Roman letters - since they were similar in appearance to them.

An alternative theory belongs to Alfred Cooper, who suggested looking at the Roman counting system from a physiological point of view. Cooper believes that I, II, III, IIII are a graphical representation of the number of fingers of the right hand that the trader throws out when calling the price. V is the extended thumb, which together with the palm forms a figure similar to the letter V.

That is why Roman numerals add up not only ones, but also add them with fives - VI, VII, etc. - this is the thumb thrown back and the other fingers of the hand extended. The number 10 was expressed by crossing the hands or fingers, hence the symbol X. Another option was to simply double the number V, getting an X. Large numbers were transmitted using the left palm, which counted tens. So gradually the signs of ancient finger counting became pictograms, which then began to be identified with the letters of the Latin alphabet.

Modern Application

Today in Russia, Roman numerals are needed, first of all, to record the number of the century or millennium. It is convenient to place Roman numerals next to Arabic ones - if you write the century in Roman numerals, and then the year in Arabic, then your eyes will not be dazzled by the abundance of identical signs. Roman numerals have a certain connotation of archaism. They are also traditionally used to indicate the serial number of the monarch (Peter I), the volume number of a multi-volume publication, and sometimes the chapter of a book. Roman numerals are also used in antique watch dials. Important numbers, such as the year of the Olympiad or the number of a scientific law, can also be recorded using Roman numerals: World War II, Euclid's V postulate.

In different countries, Roman numerals are used slightly differently: in the USSR it was customary to indicate the month of the year using them (1.XI.65). In the West, the year number is often written in Roman numerals in the credits of films or on the facades of buildings.

In parts of Europe, especially in Lithuania, you can often find the days of the week designated in Roman numerals (I – Monday, and so on). In Holland, Roman numerals are sometimes used to denote floors. And in Italy they mark 100-meter sections of the route, marking, at the same time, every kilometer with Arabic numerals.

In Russia, when writing by hand, it is customary to emphasize the Roman numerals below and above at the same time. However, often in other countries, the underscore meant increasing the case of the number by 1000 times (or 10,000 times with a double underscore).

There is a common misconception that modern Western clothing sizes have some connection with Roman numerals. In fact, the designations are XXL, S, M, L, etc. have no connection with them: these are abbreviations of the English words eXtra (very), Small (small), Large (large).

To designate numbers in Latin, combinations of the following seven characters are accepted: I (1), V (5), X (10), L (50), C (100), D (500), M (1000).

To remember the letter designations of numbers in descending order, a mnemonic rule was invented:

We Give Juicy Lemons, Vsem Ix (respectively M, D, C, L, X, V, I) is enough.

If the sign denoting a smaller number is to the right of the sign denoting a larger number, then the smaller number should be added to the larger one, if on the left, then subtract, namely:

VI - 6, i.e. 5+1
IV - 4, i.e. 5 - 1
XI - 11, i.e. 10 + 1
IX - 9, i.e. 10 - 1
LX - 60, i.e. 50 + 10
XL - 40, i.e. 50 - 10
CX - 110, i.e. 100 + 10
XC - 90, i.e. 100-10
MDCCCXII - 1812, i.e. 1000 + 500 + 100 + 100 + 100 + 10 + 1 + 1.

Different designations for the same number are possible. For example, the number 80 can be written as LXXX (50 + 10 + 10 + 10) and as XXX (100 - 20).

To write numbers in Roman numerals, you must first write the number of thousands, then hundreds, then tens, and finally units.

I (1) - unus (unus)
II (2) - duo (duo)
III (3) - tres (tres)
IV (4) - quattuor (quattuor)
V (5) - quinque
VI (6) - sex (sex)
VII (7) - septera (septem)
VIII (8) - octo (octo)
IX (9) - novem (novem)
X (10) - decern (decem)
XI (11) - undecim (undecim)
XII (12) - duodecim (duodecim)
ХШ (13) - tredecim (tradecim)
XIV (14) - quattuordecim (quattuordecim)
XV (15) - quindecim (quindecim)
XVI (16) - sedecim (sedecim)
XVII (17) - septendecim (septendecim)
XVIII (18) - duodeviginti (duodeviginti)
XIX (19) - undeviginti (undeviginti)
XX (20) - viginti (viginti)
XXI (21) - unus et viginti or viginti unus
XXII (22) - duo et viginti or viginti duo, etc.
XXVIII (28) - duodetriginta (duodetriginta)
XXIX (29) - undetriginta (undetriginta)
XXX (30) : triginta (triginta)
XL (40) - quadraginta (quadraginta)
L (5O) - quinquaginta (quinquaginta)
LX (60) - sexaginta (sexaginta)
LXX (70) - septuaginta (szltuaginta)
LXXX180) - octoginta (octoginta)
KS (90) - nonaginta (nonaginta)
C (100) centum (centum)
CC (200) - ducenti (ducenti)
CCC (300) - trecenti (trecenti)
CD (400) - quadrigenti (quadrigenti)
D (500) - quingenti (quingenti)
DC (600) - sescenti (sescenti) or sexonti (sextonti)
DCC (700) - septigenti (septigenti)
DCCC (800) - octingenti (octingenti)
CV (DCCC) (900) - nongenti (nongenti)
M (1000) - mille (mille)
MM (2000) - duo milia (duo milia)
V (5000) - quinque milla (quinque milia)
X (10,000) - decem milia (decem milia)
XX (20000) - viginti milia (viginti milia)
C (100000) - centum milia (centum milia)
XI (1,000,000) - decies centena milia (decies centena milia).

If suddenly an inquisitive person asks why the Latin letters V, L, C, D, M were chosen to denote the numbers 50, 100, 500 and 1000, then we will immediately say that these are not Latin letters at all, but completely different signs.

The fact is that the basis for the Latin alphabet was the Western Greek alphabet. It is to him that the three signs L, C and M go back. Here they denoted aspirated sounds, which were not in the Latin language. When the Latin alphabet was drawn up, they turned out to be superfluous. They were adapted to represent numbers in the Latin alphabet. Later they coincided in spelling with Latin letters. Thus, the sign C (100) became similar to the first letter of the Latin word centum (hundred), and M (1000) - to the first letter of the word mille (thousand). As for the sign D (500), it was half of the sign F (1000), and then it began to look like a Latin letter. The sign V (5) was just the upper half of the sign X (10).