Class 7 Maths Part 1 Chapter 6, Number Play, turns number theory into engaging puzzles—height-order sequences, odd/even parity arguments, 3 × 3 and 4 × 4 magic squares (including the Chautisa Yantra at Khajuraho), the Virahanka–Fibonacci sequence in poetry and nature, and cryptarithm puzzles.
What Class 7 Mathematics Chapter 6 Covers
6.1–6.2 Numbers Tell Us Things & Picking Parity solves logical ordering puzzles (‘how many taller people stand in front’) and uses odd/even parity rules for sums and products to prove when a grid tiling or coin puzzle is possible or impossible.
6.3 Some Explorations in Grids (Magic Squares) systematically constructs 3 × 3 magic squares using 1 to 9 (magic sum 15, centre 5), generalises them algebraically, and explores India’s historic 4 × 4 magic square at Parshvanatha temple, Khajuraho (magic sum 34).
6.4–6.5 Virahanka–Fibonacci Numbers & Digits in Disguise discovers the sequence 1, 2, 3, 5, 8, 13, 21, \dots through Sanskrit prosody (short 1-beat and long 2-beat syllables studied by Pingala, Virahanka, Gopala and Hemachandra) and staircase climbs, and solves letter-digit cryptarithms.
Exercises in Chapter 6
- Figure it Out exercise sets and Summary with solved walkthroughs.
Read Class 7 Mathematics Chapter 6 Online
More Chapters
- Previous: Chapter 5: Parallel and Intersecting Lines
- Next: Chapter 7: A Tale of Three Intersecting Lines
- Hindi medium: Class 7 Maths Part 1 Chapter 6 PDF in Hindi (Ganita Prakash)
- All Mathematics chapters and the other Class 7 books: Class 7 NCERT books 2026-27
- All Class 1 to 12 NCERT Textbooks: NCERT Books PDF (Class 1–12)
- Every book chapter by chapter: NCERT chapter wise PDF
FAQ
Why must the centre number of a 3×3 magic square using the numbers 1 to 9 always be 5?
The sum of 1 to 9 is 45, so each of the three rows, columns and diagonals must add up to 45 ÷ 3 = 15. Only the middle number 5 belongs to four different 3-number combinations that sum to 15, so 5 must occupy the centre cell.
How do the Virahanka–Fibonacci numbers arise from poetic metres?
Counting the number of rhythmic patterns of length n beats using short syllables (1 beat) and long syllables (2 beats) gives 1, 2, 3, 5, 8, 13, 21, \dots, where each term is the sum of the two preceding terms (F_n = Fn-1 + Fn-2).