Page 27 - Math Genius C3

E:\Working\Orange_Education\Math_Genius_3\Open_Files\CHAP_01
\ 01-Oct-2025 Bharat Arora Proof-10 Reader’s Sign _______________________ Date __________

Roman numerals I V X L C D M Practice time 1g
Hindu-Arabic numerals 1 5 10 50 100 500 1000
1. Write the Roman numerals for the following numbers.
The Roman numeral system uses a combination of letters to represent numbers. It does

not use place value and has no symbol for zero. Numbers are formed by following the (a) 16 (b) 25 (c) 39 (d) 27
four main rules: 2. Write the Hindu-Arabic numerals for the following.

Rule 1: If a symbol is repeated, its value is added as many times (a) XVIII (b) XXIX (c) XXXVII (d) XXXIV
as it occurs. 3. Fill in the blanks.

For example: (a) II = 1 + 1 = 2 (b) III = 1 + 1 + 1 = 3 (a) The Roman numeral for 26 is __________.
(c) XX = 10 + 10 = 20 (b) The successor of XXX is ____________.
Rule 2: If the smaller numeral is to the left of the bigger numeral, subtract it from the (c) The predecessor of 20 in Roman numerals is ____________.

bigger numeral. (d) The greatest 1-digit number in Roman numerals is ____________.

For example: (a) IV = 5 – 1 = 4 (b) IX = 10 – 1 = 9 (c) XL = 50 – 10 = 40 (e) When we add V to X and then subtract I from the number, we get ____________.

Rule 3: If the smaller numeral is to the right of the bigger numeral, add the two numerals.

For example: (a) VI = 5 + 1 = 6 (b) XI = 10 + 1 = 11 (c) LX = 50 + 10 = 60
Rule 4: If the smaller numeral is between two numerals of greater value, subtract the math Mind Map Creative Thinking

smaller numeral from the greater numeral to the right. Numbers up tO 9999

For example: (a) XIV = 10 + (5 – 1) = 10 + 4 = 14 (b) XIX = 10 + (10 – 1) = 10 + 9 = 19
4-Digit Numbers Place Value of a Number

Think Tank Logical Thinking Smallest number 1000 Greatest number 9999 Value of each digit in a number
List 5 places where we use Roman numerals to write numbers. • multiply the digit with 1000, if it is in the thousands place.
Face Value of a Number • multiply the digit with 100, if it is in the hundreds place.
The Roman numerals for the first 30 Hindu-Arabic numbers are shown below: Face value is the actual value of the digit in a number • multiply the digit with 10, if it is the tens place.
• multiply the digit with 1 if it is in the ones place.
1 I 11 XI 21 XXI Example: Face value of 4 in 485 is 4. Example: Place value of 4 in 485 is 400

2 II 12 XII 22 XXII Expanded Form Even and Odd numbers

3 III 13 XIII 23 XXIII The number represented as the sum of the place values Every even number ends with 2, 4, 6, 8 or 0.
of its digits. Example: 56, 742, 1230
4 IV 14 XIV 24 XXIV Example: 485 = 400 + 80 + 5 Every odd number ends with 1, 3, 5, 7 or 9.
Example: 51, 637, 1459
5 V 15 XV 25 XXV
Formation of Greatest and Smallest Numbers Estimation (Rounding Off)
6 VI 16 XVI 26 XXVI
To form the greatest number, arrange the given digits in To find an approximate value is known as estimation.
7 VII 17 XVII 27 XXVII descending order. Example: 33 is rounded off to its nearest 10 which is 30
Example: 8643 is the greatest 4-digit number formed
8 VIII 18 XVIII 28 XXVIII using the digits 6, 3, 8, 4. 30 31 32 33 34 35 36 37 38 39 40
To form the smallest number, arrange the given digits in
9 IX 19 XIX 29 XXIX ascending order. Example: 67 is rounded off to its nearest 10 which is 70
10 X 20 XX 30 XXX Example: 3468 is the smallest 4-digit number formed 60 61 62 63 64 65 66 67 68 69 70
using the digits 6, 3, 8, 4.

Mathematics-3 25