Class 7 Maths - MAHARASHTRA
Number Play
The chapter 'Number Play' in Class 7 Mathematics under the Maharashtra State Board (MSBSHSE) introduces students to the fascinating world of numbers through puzzles, magic tricks with numbers, and divisibility tests. It helps students understand the general form of two-digit and three-digit numbers, expressing them as sums of multiples of powers of ten. This chapter is crucial for building a strong foundation in algebraic thinking and logical reasoning, which are essential for solving higher-level board exam problems efficiently.
Start Learning FreeKey Concepts
General Form of a Two-Digit Number
Any two-digit number 'ab' can be written in its expanded form as 10a + b, where 'a' is the ten's digit and 'b' is the unit's digit.
General Form of a Three-Digit Number
A three-digit number 'abc' can be expressed in expanded form as 100a + 10b + c, where 'a', 'b', and 'c' are the hundreds, tens, and units digits respectively.
Reversing Digits of a Two-Digit Number
When the digits of a two-digit number 10a + b are reversed, the new number becomes 10b + a.
Number Puzzles and Magic Tricks
Mathematical games where choosing a number, performing specific arithmetic operations, and arriving at a predictable final answer rely on algebraic properties.
Divisibility Rules for 3 and 9
A number is divisible by 3 or 9 if the sum of its digits is a multiple of 3 or 9 respectively.
Important Formulas
Board Exam Info
In the Maharashtra (MSBSHSE) Class 7 Mathematics curriculum, 'Number Play' typically carries around 4 to 6 marks in the semester exams. Common question types include writing numbers in general form, proving puzzles algebraically, and applying divisibility tests to find unknown digits.
Frequently Asked Questions
Why do we write numbers like 10a + b instead of just ab?
In algebra, writing 'ab' means 'a multiplied by b'. To represent a two-digit number where 'a' is the tens digit and 'b' is the units digit, we must write it as 10a + b.
How do I know if a number puzzle solution is correct?
You can verify your puzzle by substituting specific digits for the variables (like a and b) and checking if the mathematical statement holds true.
Will questions from this chapter appear in higher classes?
Yes, the concept of general form of numbers and algebraic proofs forms the basis for simultaneous linear equations and number systems in Class 8 and 9.
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