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\\October 12, 2025 9:48 AM Bharat Arora P-9 Reader _________________________ Date: ___________________74

Rule 3: The smaller numeral written to the left of the larger numeral is always subtracted
from the larger numeral.

Examples: (a) IV = 5 – 1 = 4 (b) XL = 50 – 10 = 40
(c) XC = 100 – 10 = 90

Note: The roman numeral ‘I’ can only be subtracted from V and X. X can be
subtracted from L and C only. C can

be subtracted from D and M only. Challenge Question
V, L and D are never subtracted. Replace “?” with a Roman

Rule 4: When the smaller numeral is placed numeral to make this true: Critical Thinking
between two larger numerals, then (X ? V) + XV = LX
it is always subtracted from the larger numeral immediately following it.

Examples: (a) XIV = 10 + (5 – 1) = 14
(b) XIX = 10 + (10 – 1) = 19

(c) XLIX = (50 – 10) + (10 – 1) = 40 + 9 = 49

Example 1: Write the following Hindu-Arabic numerals in Roman numerals.
(a) 48 (b) 97 (c) 175 (d) 389
Solution: Math Insight

(a) 48 = 40 + 8 = XL + VIII = XLVIII Learn the mnemonic to remember

(b) 97 = 90 + 7 = XC + VII = XCVII the sequence of Roman numerals:
I Value Xylophones Like
(c) 175 = 100 + 70 + 5 = C + LXX + V = CLXXV Cows Do Milk

(d) 389 = 300 + 80 + 9 = CCC + LXXX + IX = CCCLXXXIX

Example 2: Write the following Roman numerals in Hindu-Arabic numerals.
(a) XLV (b) LXV (c) CXXIX (d) CCCXLV

Solution:
(a) XLV = (50 – 10) + 5 = 40 + 5 = 45 Life Skills
List five things or objects, where
(b) LXV = 50 + 10 + 5 = 65 you often see the use of Roman

(c) CXXIX = 100 + 20 + 9 = 129 numerals around you.

(d) CCCXLV = 100 + 100 + 100 + (50 – 10) + 5 = 300 + 40 + 5 = 345

Think Tank Critical Thinking
Find the following and fill in the blanks using Roman numerals.
1. Your father’s age = ______________________
2. Your mother’s age = ______________________
3. Date of birth of your best friend = ______________________
4. Date on which India became independent = ______________________

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