Knowing our Numbers
- Large numbers upto one crore
- Reading and writing of large numbers
- Comparing large numbers
- Indian System of Numeration
- International System of Numeration
- Use of large numbers
- Estimation of numbers
SEE ALSO : Chapter 6: Integers
- Use of brackets
- Roman numerals
- Natural numbers
- Predecessor and successor of a natural number
- Whole numbers: The natural numbers along with zero form the collection of whole numbers.
- Representation of whole numbers on the number line
- Addition and subtraction of whole numbers on the number line
- Division of a whole number by zero is not defined
SEE ALSO : Chapter 2: Whole Numbers
- Patterns in whole numbers
Properties of whole numbers
- Closure property
- Commutativity of addition and multiplication
- Associativity of addition multiplication
- Distributivity of muliplication over addition
- Identities for addition and multiplication
Playing with Numbers
- Factors and multiples
- Number of factors of a given number is finite
- Number of multiples of a given number is infinite
SEE ALSO : Chapter 3: Playing With Numbers
- Perfect number: A number for which sum of all its factors is equal to twice the number.
- Prime and composite numbers
- Tests for divisiblity of numbers by 2, 3, 4, 5, 6, 8, 9 and 11
- Common factors and common multiples
- Coprime numbers
- Product of two consecutive whole numbers is divisible by 2
- If a number is divisible by another number, then it is divisible by each of the factors of that number.
- If a number is divisible by two coprime numbers, then it is divisibile by their product also.
- If two given numbers are divisible by a number, then their sum is also divisible by that number.
- If two given numbers are divisible by a number, then their difference is also divisible by that number.
SEE ALSO : Chapter 4: Basic Geometrical Ideas
Prime factorisation of a number
- Highest Common Factor (HCF) of two or more numbers
- Least Common Multiple (LCM) of two or more numbers
- Use of HCF and LCM in problems of day to day life.
SEE ALSO : Chapter 5: Understanding Elementary Shapes