What are Roman Numerals?
Roman Numerals
Roman Numerals & How They Began
Historians believe Roman Numerals began as a tally system. Shepherds on the hills and in the fields around Rome would cut marks into sticks to keep track of how many sheep or goats were in their care.
Each animal was counted then recorded on a wooden stick with a single notch cut with a knife. Every fifth sheep was recorded on the stick with two notches which formed a V. Each tenth sheep was recorded with two cuts to form an X.
This method of record keeping was still used by Italian shepherds during the Nineteenth Century.
Hindu-Arabic Numerals vs. Roman Numerals
The Hindu-Arabic numerals consist of a set of ten symbols i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9 and 0 that originated in India and was later introduced to Europe through the writings of Middle Eastern mathematicians.
Till now we have learnt about the Hindu-Arabic system, but this is not the only system of numeration. We have seen different type of numerals used in clocks and for representing classes. This is referred as the Roman Numeral system.
Roman Numeral system is one of the early systems of writing numerals developed many centuries ago.
In the Roman Numeral system there are 7 symbols i.e. I, V, X, L, C, D and M unlike Hindu-Arabic, which has 10 symbols.
The Roman Numerals do not follow a place value system and each symbol has a certain value given to it.
There is no symbol for ‘0’ in this system.
The Roman Numerals for the numbers 1-10 are shown below-
This is followed by XI for 11, XII for 12,… till XX for 20.
Rules for Roman Numeral System
Any symbol in Roman numerals is not repeated more than three times.
For example, 40 in Roman Numberals is written as XL and not XXXX.
The symbols V, L and D are never repeated.
For example, 150 in Roman Numerals is written as CL and not LLL.
If a symbol is repeated, its value is added as many times as it occurs.
For example, II is equal 2, XX is 20 and XXX is 30.
If a symbol of smaller value is written to the right of a symbol of greater value, its value gets added to the value of greater symbol.
For example, VI = 5 + 1 = 6, XII = 10 + 2 = 12
and LXV = 50 + 10 + 5 = 65
If a symbol of smaller value is written to the left of a symbol of greater value, its value is subtracted from the value of the greater symbol.
For example, IV = 5 – 1 = 4, IX = 10 – 1 = 9
XL= 50 – 10 = 40, XC = 100 – 10 = 90
If a symbol of smaller value is written between the symbols of greater value, then its value is subtracted from the symbol of the greater value which is wriiten immediately after the symbol of the smaller value.
For example, the value of XIV is 10 + (5 – 1) i.e. 14.
The symbols V, L and D are never written to the left of a symbol of greater value, i.e. V, L and D are never subtracted.
For example, the number 45 in Roman Numerals is written as XLV i.e. 50-10+5 and not VL i.e. 50-5.
The symbol I can be subtracted from V and X only.
For example, we write 49 in Roman Numerals as XLIX i.e. 50 – 10 + (10 – 1) and not IL i.e. 50-1.
The symbol X can be subtracted from L, M and C only.
For example, we write 450 in Roman Numberals as CDXC i.e. 500 – 50 + 50 - 10 and not as XD i.e. 500 – 10.
Examples-
Write in Roman Numerals:
32
= 30 + 2
= XXXII
53
= 50 + 3
= LIII
78
= 50 + 20 + 8
= LXXVIII
FUN FACT
Here are few famous names that become recognizable when we add the roman numerals to them.
Charles I – The English king who lost his head.
Dalai Lama XIV – Tibetan monk leader currently living in exile.
Henry VIII – The king of England who is famous because a couple of his wives lost their heads.
Louis XVI – King of France who lost his head.
Pope Gregory XIII – gave the world the calendar many of us are familiar with.
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