Master Chapter 6 Class 7 - Number Play - Ganita Prakash with comprehensive NCERT Solutions, Practice Questions, MCQs, Sample Papers, Case Based Questions, and Video lessons.
Start Learning NowWelcome to Chapter 6, Number Play, from your Class 7 Maths book, Ganita Prakash.
This chapter is a little different from the others. It's not about learning new types of calculations. Instead, it’s about becoming a "number detective." We're going to "play" with numbers to discover the hidden patterns, rules, and logical properties that they follow.
This chapter is all about sharpening your reasoning skills. You'll learn how to solve puzzles and prove that some things are possible (or impossible!) not by trying every single combination, but by using pure logic.
We will explore several different "games" and "puzzles" to uncover the secret rules of numbers.
Picking Parity (Even and Odd Numbers)
This is the first and most important rule of play. Parity is simply the property of a number being even or odd. We'll investigate the simple, unbreakable rules that govern them:
Even + Even = Even
Odd + Odd = Even
Even + Odd = Odd
You'll see how these simple rules can instantly solve puzzles. For example, can you pick 5 odd numbers from a list and make them add up to 30 (an even number)? We'll learn why this is logically impossible, without even needing to check the numbers.
Magic Squares
We'll move on to a classic number puzzle: the Magic Square. In a $3 \times 3$ grid using the numbers 1 through 9, the rows, columns, and diagonals must all add up to the same "magic sum." We'll use logic to discover its secrets:
Why must the magic sum always be 15?
Why must the number 5 always be in the center?
Which numbers can (and cannot) go in the corners?
Nature's Favorite Sequence (Virahāńka-Fibonacci)
Next, we'll explore one of the most famous patterns in all of mathematics: the sequence 1, 2, 3, 5, 8, 13... You'll learn about its fascinating origin in ancient Indian poetry (counting rhythms of syllables) and the simple rule that generates it: each number is the sum of the two before it.
Digits in Disguise (Cryptarithms)
Finally, we'll become code-breakers. We'll solve cryptarithms—puzzles where digits are hidden by letters. You'll use your logic to figure out what digit each letter must represent in problems like:
T + T + T = UT
This chapter is all about developing your number sense and logical thinking. At Teachoo, we'll walk you through the logic of each puzzle, from parity to magic squares, so you can learn to think like a mathematician.
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