We're going to write the given number using Roman numerals.
The basic Roman numeral symbols are given here
with their corresponding values. We can combine these symbols
to represent the given numbers, using roman numerals.
So for a quick review. Numbers are formed by combining the symbols together,
if the numbers are placed from left to right in order of value, starting with the
largest value, followed by the smaller values,
the values are added as we see here. The two X's represent twenty,
the V represents five,
the three I's represent three. Twenty plus five, plus three
equals twenty eight. However, to avoid repeated characters,
the smaller numeral comes before a larger numeral. The smaller is subtracted from
the larger.
So for example instead of using four capitalize I's for four,
we put an I before a V or a one before a five.
This represents five minus one or four.
For nine hundred ninety seven, notice how we have a C before an M,
this is a one hundred before a thousand. This represents one thousand minus one
hundred or nine hundred,
followed by an X before a C
or a ten before a one hundred. One hundred minus ten is ninety,
followed by five, plus one, plus one or plus seven,
for nine hundred ninety seven. This subtraction principal can be a little involved because there are
restrictions.
You can only subtract a power of ten,
and only from the next two higher digits, where the digits are
the symbols given here. Which means
only I, X and C can be subtracted,
and I can only be subtracted from
V and X. X can only be subtracted from
L and C, and C can be subtracted only from
D and M. Let's go back and look at our examples.
For fifty six, notice how we can use L for fifty,
and then for six, we can use a V and a capital I,
where the V would come first, followed by the I. This would be fifty plus six
or fifty six. For one hundred eighty seven,
we can use a C for one hundred. Now for eighty we can use
and L followed by 3 X's.
So there's fifty plus ten,
plus ten, plus ten are eighty. And then for seven,
we can use a V and two I's.
Because we have the largest values first,
followed by the smaller values, we add all the values,
giving us one hundred eighty even. Now for the next three,
we'll have to use the subtraction principal. For example, for four hundred,
we can't use four C's because we have to avoid
repeating four symbols. So what we can do is put
a C before a D, which would be a one hundred before a five hundred,
meaning we would subtract. So if we have C and then D,
this represents four hundred because this is five hundred minus one hundred.
And then for twenty we can use two X's, but for nine,
we can't use a V and four I's. We'll have to use the subtraction principal.
If we put in I before an X, that's like putting a one before a ten.
Meaning we subtract, ten minus one is nine.
So we'll have I and then X. Again this is four hundred,
this is twenty, and this is nine. For nine hundred forty nine,
we'll start with nine hundred, using the subtraction principal.
We'll put a one hundred before a thousand,
or a C before an M. So there's nine hundred.
And then for forty we cannot use 4 X's,
because we cannot repeat four symbols.
so we'll use a ten before a fifty,
or an X before an L. And then for nine, again we'll use
and I before an X or a one before a ten.
So here we have nine hundred, here we have forty,
and here we have nine. Finally for two thousand nine hundred ninety four,
we'll start with the two thousand, which is two M's.
Now for nine hundred, again we'll have to use
a one hundred before a one thousand, or a C before an M.
Meaning we'll subtract one hundred from a thousand to get nine hundred.
And then for ninety, we'll have to use
the subtraction principal, and put a ten before a hundred,
or an X before a C, so there's the ninety.
Finally for four, we can't use four I's, we'll have to use an I before a V,
or a one before a five, so we subtract.
See we have I and then V. So we have two thousand
nine hundred ninety four.
I hope you found this helpful.