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Roman numerals are a numerical system used in ancient Rome and are still in common use today.

Roman numeral symbol

I 1

Two-two

Three-three

Four-four

Five to five levels

VI - 6

Seven to seven days

Eight-eight

Nine to nine

x– 10

Xi– 1 1

XII– 12

XIII– 13

XIV– 14

XV– 15

XVI– 16

XVII– 17

XVIII– 18

XIX– 19

XX–20

XXI–2 1

Twenty-two to twenty-two years old

28-

28

XXIX - 29

XXX - 30

XL - 40

L - 50

LX - 60

LXX - 70

LXXX - 80

XC - 90

XCIX - 99

C - 100 centum

CI - 10 1 centum

et unus

CXCIX - 199

CC - 200

CCC - 300

CD - 400

D - 500

DCLXVI - 666

M - 1，000

MCMXCIX- 1.999

MM-2000

Um-

3,000

MMMM-4000

MMMMCMXCIX-4999

5000 pounds

spelling rules

There are seven Roman numerals * * *, which are I( 1), V(5), X( 10), L(50), C( 100), D(500) and M (10). Any positive integer can be expressed according to the following rules.

Repeat several times: 1 Roman numeral is repeated several times, indicating several times of this number.

Add right and subtract left: write a smaller Roman numeral to the right of the larger Roman numeral, indicating that the larger number is added with the smaller number. Write 1 the smaller Roman numeral to the left of the larger number, indicating that the larger number reduces the number. However, the left subtraction cannot span one digit. For example, 99 can't be represented by IC, but only by XCIX. In addition, the minus sign on the left cannot exceed 1 digit, for example, 8 is written as VIII instead of IIX. Similarly, the number added to the right cannot exceed 3 digits. For example, 14 is written as XIV instead of XIIII.

Add lines and multiply by thousands: add 1 horizontal line above 1 Roman numeral or write m at the bottom right, which means that this number is multiplied by 1000, which is 1000 times the original number. Similarly, if there are two horizontal lines on it, it is 1000000 times the original number.

Company limit: the same company can only appear three times. For example, 40 cannot be expressed as XXXX, but as XL. However, because IV is the initial word of IVPITER (there are no J and U in the ancient Roman alphabet), IIII is sometimes used instead of IV.

annual report

When Roman numerals are used in chronology, their spelling rules are the same as numbers.

use

Public memorial building

clocks and watches

calendar

Year of TV program production

There are seven Roman numerals * * *, which are I( 1), V(5), X( 10), L(50), C( 100), D(500) and M (10). Any positive integer can be expressed according to the following rules.

Repeat several times: 1 Roman numeral is repeated several times, indicating several times of this number.

Add right and subtract left: write a smaller Roman numeral to the right of the larger Roman numeral, indicating that the larger number is added with the smaller number. Write 1 the smaller Roman numeral to the left of the larger number, indicating that the larger number reduces the number. However, the left subtraction cannot span one digit. For example, 99 can't be represented by IC, but only by XCIX. In addition, the minus sign on the left cannot exceed 1 digit, for example, 8 is written as VIII instead of IIX. Similarly, the number added to the right cannot exceed 3 digits. For example, 14 is written as XIV instead of XIIII.

Add lines and multiply by thousands: add 1 horizontal line above 1 Roman numeral or write m at the bottom right, which means that this number is multiplied by 1000, which is 1000 times the original number. Similarly, if there are two horizontal lines on it, it is 1000000 times the original number.

Company limit: the same company can only appear three times. For example, 40 cannot be expressed as XXXX, but as XL. However, because IV is the initial word of IVPITER (there are no J and U in the ancient Roman alphabet), IIII is sometimes used instead of IV.