Class 7 Maths - ODISHA
Number Play
The Chapter 'Number Play' in Class 7 Mathematics for Odisha Board (BSE) introduces students to the fascinating world of numbers, puzzles, and divisibility. It helps develop logical thinking and mental math skills by exploring patterns in numbers, properties of digits, and mathematical tricks. Students learn to express numbers in generalized form using alphabets like a, b, and c. This chapter is essential for building a strong foundation in algebra and number theory, making problem-solving more intuitive. It carries significant weightage in the BSE Odisha exams, testing both conceptual understanding and quick application of number puzzles.
Start Learning FreeKey Concepts
Generalized Form of Numbers
Writing a two-digit number like ab as 10a + b and a three-digit number like abc as 100a + 10b + c based on place value.
Number Puzzles and Games
Solving mathematical riddles and letter puzzles where alphabets represent unknown digits following basic arithmetic rules.
Divisibility by 2, 5, and 10
Quick tests to check if a number is divisible by 2 (even last digit), 5 (ends in 0 or 5), or 10 (ends in 0).
Divisibility by 3 and 9
Rules stating that a number is divisible by 3 or 9 if the sum of its digits is a multiple of 3 or 9 respectively.
Reversing Digits and Sums
Observing patterns when reversing the digits of a number, such as the sum of a two-digit number and its reverse being always divisible by 11.
Important Formulas
Board Exam Info
In the BSE Odisha Class 7 Mathematics examinations, 'Number Play' typically carries around 4 to 6 marks. Common question types include short-answer questions on finding missing digits in addition or multiplication puzzles, checking divisibility of large numbers, and expressing numbers in their generalized forms.
Frequently Asked Questions
What is the generalized form of a two-digit number?
It is written as 10a + b, where 'a' is the ten's digit and 'b' is the unit's digit.
How do we know if a large number is divisible by 9?
Add all the digits of the number. If the sum is divisible by 9, then the entire number is divisible by 9.
Why do we study number puzzles in Class 7?
Number puzzles help improve mental calculation, logical reasoning, and lay the groundwork for solving algebraic equations easily.
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