Olympiad Notes: Numerals | Math Olympiad for Class 2 PDF Download

Introduction

Numerals are symbols or numbers used to show quantity. We use numerals for counting, comparing, and calculations.

Olympiad questions include:

• Writing numbers in figures and words
• Understanding place value and face value
• Writing expanded form
• Comparing numbers
• Ordering numbers (ascending/descending)
• Using ordinal numbers
• Reading and writing Roman numerals

Numeral and Number Name

• Numeral: A number written in digits. 
  Example: 45
• Number Name: A number written in words. 
  Example: Forty-five
• Tip: Use a hyphen between tens and ones: Twenty-one, Thirty-two

Numbers and Number Names

Place Value and Face Value

Place Value: Place value is the value of a digit depending on its position in a number.

Face Value: Face value is the value of the digit itself, ignoring its position.

Example: 45

• 4 → Place value = 40, Face value = 4
• 5 → Place value = 5, Face value = 5

Expanded Form

Expanded form is writing a number to show the value of each digit.

Examples:

• 450 = 400 + 50 + 0
• 36 = 30 + 6
• 50 = 50 + 0 

Comparing Numbers

Comparing numbers is finding which number is greater, smaller, or equal.

Rules:

• The number with more digits is greater.
• If the number of digits is the same, compare digits from left to right.

Examples:

• 45 < 67
• 32 > 21
• 80 = 80

Symbols: > (greater), < (less), = (equal)

Ascending and Descending Order

Ascending Order: Arranging numbers from smallest to largest.

Descending Order: Arranging numbers from largest to smallest.

Example:

• Ascending: 12, 24, 36, 48
• Descending: 90, 70, 50, 30

Ordinal Numbers

Ordinal numbers show the position or rank of a person or thing.

Examples: 
1st → First, 
2nd → Second, 
3rd → Third, 4th → Fourth

Sentence: Riya came 2nd in the race.

Roman Numerals

• Roman numerals are numbers written with letters.
• Used in clocks, books, events, and awards.

Roman Numerals 1–20

Rules:

1. Smaller numeral after bigger → add. Example: VI = 5 + 1 = 6

2. Smaller numeral before bigger → subtract. Example: IV = 5 – 1 = 4

3. Repeating the same numeral → addition. Example: III = 1 + 1 + 1 = 3

Examples in Use:

• Clock: 12 → XII
• Book chapters: Chapter 5 → Chapter V
• Events: Olympics XX → 20th Olympic Games