Roman Numbers

• Origin
• System
• Fractions with roman numbers
• Actual Roma
• Then, a video

Index:

Roman numeration is a numbering system that was developed in Ancient Rome and was used throughout the Roman Empire, being maintained after its disappearance and still used in some areas. This system uses some capital letters as symbols to represent certain values.

Origin:

The underlying form of this pattern employs the symbols I and V (representing 1 and 5) as simple tally marks, to build the numbers from 1 to 9. Each marker for 1 (I) adds a unit value up to 5 (V), and is then added to (V) to make the numbers from 6 to 9. Finally the unit symbol for the next power completes a "finger count" sequence.At some early time the Romans started to use the shorter forms IV ("one less than 5") for IIII, and IX ("one less than 10") for VIIII – a convention that has been widely, although not universally, followed ever since. This convention is called "subtractive" notation, as opposed to the "additive" notation of IIII and VIIII. Thus the numbers from 1 to 10 are generally written as.

System:

The multiples of 10, from 10 to 100, are written according to the same pattern, with X, L, and C taking the place of I, V, and X.Note that 40 is usually written XL ("10 less than 50") rather than XXXX, and 90 as XC ("10 less than 100") rather than LXXXX: following the same "subtractive" pattern as IV and IX.Similarly, the multiples of 100, 100 to 1000.where CD is to be read as "100 less than 500" (that is, 400), and CM as "100 less than 1000" (that is, 900).Since the system has no standard symbols for 5,000 and 10,000, the full pattern cannot be extended to the multiples of 1000 – restricting the "thousands" range of "normal" Roman numerals to 1,000, 2,000 and 3,000:

Though the Romans used a decimal system for whole numbers, reflecting how they counted in Latin, they used a duodecimal system for fractions, because the divisibility of twelve (12 = 22 × 3) makes it easier to handle the common fractions of ​1⁄3 and ​1⁄4 than does a system based on ten (10 = 2 × 5). On coins, many of which had values that were duodecimal fractions of the unit as, they used a tally-like notational system based on twelfths and halves. A dot (·) indicated an uncia "twelfth", the source of the English words inch and ounce; dots were repeated for fractions up to five twelfths. Six twelfths (one half) was abbreviated as the letter S for semis "half". Uncia dots were added to S for fractions from seven to eleven twelfths, just as tallies were added to V for whole numbers from six to nine.[56]

Fractions with roman numbers:

Actual Roma:

Then, a video:

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