**High School Number Sense Lesson 18: Roman Numeral Operations**

This concept showed up

**9 times**this year between questions 11 and 19, inclusive. The average placement was question # 16, and the median spot was

**question # 18**. This is a continuation of Monday's post: RomanToArabic, which you may want to review now if you haven't seen it yet.

**Number Dojo Level: 65**

The secret to this skill is quickly being able to convert back and forth from Roman Numerals to Arabic numbers. You are typically given two or more Roman numerals to add, subtract, multiply, divide, or square. In high school, the answer will need to be written in Arabic numbers, which will be indicated on the test. (For middle school, the answer may have to be written as a Roman numeral).

**Example 1: MIX + MVI = ___ (Arabic number)**

- Convert each Roman numeral to its Arabic number equivalent. MIX =
**1009**and MVI =**1006**. - Add the numbers together. 1009 + 1006 =
**2015**.

**Example 2: CXLIV - XCIX = ___ (Arabic number)**

- Convert each to an Arabic number: CXLIV =
**144**and XCIX =**99**. - Subtract the numbers. 144 - 99 =
**45**.

**Example 3: DCXIV x XI = ___ (Arabic number)**

- Convert each to an Arabic number: DCXIV =
**614**and XI =**11**. - Multiply the numbers (which you can do quickly because you know how to Mult11). :) 614 x 11 =
**6754**.

**Example 4: MDXV ÷ III = ___ (Arabic number)**

- Convert each to an Arabic number: MDXV =
**1515**. III =**3**. - Divide the numbers (which you can do quickly because you know how to DivMultiples). :) 1515 ÷ 3 =
**505**.

**Example 5: LVI + XLIV = ___ (Roman numeral)**

- Convert each to an Arabic number: LVI =
**56**and XLIV =**44**. - Add the numbers together. 56 + 44 =
**100**. - Convert back to a Roman numeral. 100 =
**C**.

**Here's a free worksheet to help you practice RomanOper:**

romanoper.pdf |

**Up Next for High School: Mult12-19**