1. Unit 26
Roman Numerals

2. Basic Principles of Roman Numerals
Roman numerals are used in health care for some drugs and solutions. They may be used when ordering supplies.
Roman numerals use letters or symbols to represent numbers.
The key symbols are the I, V, X, L, C, D, and M.
By using these symbols, any number can be formed.

3. Basic Principles of Roman Numerals
Usually no more than three of any one symbol is used to represent a number.
If a letter or symbol is repeated in sequence, the numbers are added.
If a symbol for a smaller number is used after the symbol for a larger number, all of the numbers are added together.
If a symbol for a smaller number is used in front of the symbol for a larger number, the smaller number is subtracted from the larger number.

4. Roman Numerals Example: Convert 134 to Roman numerals.
30 = XXX
4 = V – I = IV
Therefore, 134 = CXXXIV in Roman numerals.

5. Practical Problem
The cornerstone of a hospital shows the date when the hospital was built as MCMXLVII.
When was the hospital built?

6. Practical Problem Change MCMXLVII to Arabic numbers:
The hospital was built in 1947.