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\\September 30, 2025 9:37 AM Bharat Arora P-9 Reader _________________________ Date: ___________________74

rule 3: The smaller numeral written to the left of the larger numeral is always subtracted
Practice time 1e from the larger numeral.

1. round off the following numbers to the nearest 10. examples: (a) IV = 5 – 1 = 4 (b) XL = 50 – 10 = 40

(a) 843 (b) 785 (c) 997 (d) 3265 (c) XC = 100 – 10 = 90

(e) 7545 (f) 9048 (g) 10,200 (h) 14,563 Note: The roman numeral ‘I’ can only be subtracted from V and X. X can be

2. round off the following numbers to the nearest 100. subtracted from L and C only. C can Challenge Question

(a) 2832 (b) 4567 (c) 5055 (d) 9398 be subtracted from D and M only.
V, L and D are never subtracted. Replace “?” with a Roman
(e) 7500 (f) 14,657 (g) 32,195 (h) 43,629 numeral to make this true: Critical Thinking
rule 4: When the smaller numeral is placed
3. round off the following numbers to the nearest 1000. between two larger numerals, then (X ? V) + XV = LX

(a) 23,471 (b) 43,805 (c) 60,030 (d) 1,24,350 it is always subtracted from the larger numeral immediately following it.

(e) 3,45,552 (f) 9,85,832 (g) 7,54,325 (h) 8,32,981 examples: (a) XIV = 10 + (5 – 1) = 14
(b) XIX = 10 + (10 – 1) = 19

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

There are seven basic symbols (letters of the English alphabet) example 1: Write the following Hindu-Arabic numerals in Roman numerals.

in the Roman numerals. Knowledge Desk (a) 48 (b) 97 (c) 175 (d) 389
They are given in the following table with their respective The Hindu-Arabic Solution: Math Insight
system uses ten
Hindu-Arabic numerals. symbols 0, 1, 2, 3, 4, 5, (a) 48 = 40 + 8 = XL + VIII = XLVIII Learn the mnemonic to remember
6, 7, 8 and 9, evolved (b) 97 = 90 + 7 = XC + VII = XCVII the sequence of Roman numerals:
roman Numerals I V X L C D M from Brahmi numerals. I Value Xylophones Like
Hindu-Arabic Numerals 1 5 10 50 100 500 1000 Today, this system is (c) 175 = 100 + 70 + 5 = C + LXX + V = CLXXV Cows Do Milk
used worldwide.
The first ten Roman numerals are: (d) 389 = 300 + 80 + 9 = CCC + LXXX + IX = CCCLXXXIX

I II III IV V VI VII VIII IX X Math Insight example 2: Write the following Roman numerals in Hindu-Arabic numerals.

1 2 3 4 5 6 7 8 9 10 There is no symbol for zero. (a) XLV (b) LXV (c) CXXIX (d) CCCXLV
rules for Writing roman numerals Solution:
(a) XLV = (50 – 10) + 5 = 40 + 5 = 45 Life Skills
rule 1: Repetition of a Roman numeral means addition. List five things or objects, where
examples: (a) II = 1 + 1 = 2 (b) XX = 10 + 10 = 20 (b) LXV = 50 + 10 + 5 = 65 you often see the use of Roman

(c) CCC = 100 + 100 + 100 = 300 (c) CXXIX = 100 + 20 + 9 = 129 numerals around you.

Notes: 1. The symbols I, X, C and M can be repeated up to three times only. (d) CCCXLV = 100 + 100 + 100 + (50 – 10) + 5 = 300 + 40 + 5 = 345

2. V, L and D are not repeated. Think Tank Critical Thinking
rule 2: A smaller numeral written to the right of a larger numeral is always added Find the following and fill in the blanks using Roman numerals.

to the larger numeral. 1. Your father’s age = ___________________
2. Your mother’s age = ___________________
examples: (a) XVII = 10 + 5 + 1 + 1 = 17 (b) LXV = 50 + 10 + 5 = 65 3. Date of birth of your best friend = ___________________

(c) CX = 100 + 10 = 110 4. Date on which India became independent = ___________________

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