Class 8 Maths Part 2 Chapter 6, Algebra Play, uses algebraic expressions to decode ‘Think of a Number’ magic tricks, number pyramids, calendar magic grids, maximum-product digit placement and divisibility puzzles.
What Class 8 Maths Chapter 6 Covers
6.1 and 6.2 ‘Think of a Number’ Tricks model multi-step number and birthday-date tricks with algebraic variables to show why the secret number cancels out or can be recovered.
6.3 Number Pyramids and 6.4 Fun with Grids use linear expressions in one and two variables to solve 3-layer and 4-layer number pyramids and 2×2 or 3×3 calendar grids.
6.5 The Largest Product and 6.6 Decoding Divisibility Tricks use place-value algebra and the distributive property to find which arrangement of digits gives the largest product and why repeating-digit tricks (like abcabc divisible by 7, 11 and 13) always work.
Exercises in Chapter 6
- Figure it Out exercise sets throughout the chapter with real-world applications and puzzles.
Read Class 8 Maths Chapter 6 Online
More Chapters
- Previous: Chapter 5: Tales by Dots and Lines
- Next: Chapter 7: Area
- All Maths chapters and the other Class 8 books: Class 8 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 is a 6-digit number of the form abcabc always divisible by 7, 11, and 13?
Because abcabc = abc × 1001, and 1001 = 7 × 11 × 13.
How does algebra explain ‘Think of a Number’ tricks?
By representing the unknown starting number as x and simplifying each operation step-by-step to reveal the underlying formula.