3rd Grade Roman Numerals to 20 worksheets

About this worksheet

Roman numerals are not a Common Core standard on their own — this worksheet is keyed to 3. NBT. A. 2, fluently adding and subtracting within 1,000, because that is exactly the skill hiding inside a Roman numeral. Reading I, V, and X up to 20 asks a third grader to add or subtract small values based on where a numeral sits: VI is 5 add 1 because the I comes after the V, while IV is 5 subtract 1 because the I comes before it. That single rule, order decides the operation, is the whole system, and it is also where children get stuck: they see the same two letters in IV and VI and cannot say which is which without a strategy. This worksheet teaches the strategy directly. Some questions convert a numeral to a number or a number to a numeral.

Others ask the why behind a pair like IX and XI, which use the same two letters in opposite order for opposite reasons. A few show a numeral written incorrectly, such as IIII for 4, and ask for the correct form, because knowing why IIII is wrong (a numeral may not repeat more than three times) is as important as knowing that IV is right. Real examples, a clock face, a book chapter, a king's name, show that Roman numerals still show up outside of math class. Support versions stay with I to X, standard versions go up to 15, and challenge versions work from 11 to 20, including IX, XIV, and XIX. If your child gets stuck, have them say the value of each letter first (I is 1, V is 5, X is 10) before deciding whether to add or subtract.

What your child will learn

• Convert Roman numerals I, V, and X to numbers up to 20
• Convert numbers up to 20 to Roman numerals
• Explain why a smaller numeral before a bigger one is subtracted
• Explain why a smaller numeral after a bigger one is added
• Spot and correct an incorrectly written Roman numeral