Class 8 Maths Part 1 Chapter 5, Number Play, uses algebra, parity and remainders to explore sums of consecutive numbers, ‘Always, Sometimes, or Never’ conjectures, divisibility shortcuts for 3, 9 and 11, digital roots and cryptarithm puzzles.
What Class 8 Maths Chapter 5 Covers
5.1 Is This a Multiple Of? investigates sums of consecutive numbers, odd/even parity (‘Breaking Even’, ‘Pairs to Make Fours’) and algebraic expressions for remainders.
5.2 Checking Divisibility Quickly derives why the divisibility tests for 9, 3 and 11 work by expanding numbers in powers of 10, and introduces digital roots.
5.3 Digits in Disguise and Navakankari solves letter-for-digit cryptarithms and ends with the traditional Indian strategy board game Navakankari (Nine Men’s Morris).
Exercises in Chapter 5
- Figure it Out exercise sets after each major section, with complete answer keys at the end of the chapter.
Read Class 8 Maths Chapter 5 Online
More Chapters
- Previous: Chapter 4: Quadrilaterals
- Next: Chapter 6: We Distribute, Yet Things Multiply
- Hindi medium: Class 8 Maths Part 1 Chapter 5 PDF in Hindi (Ganita Prakash)
- 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
How do you test if a number is divisible by 11 in Chapter 5?
Find the difference between the sum of its digits in odd places and the sum of its digits in even places; if that difference is 0 or a multiple of 11, the number is divisible by 11.
What is a cryptarithm (‘Digits in Disguise’)?
An arithmetic puzzle in which digits are replaced by letters, where each letter stands for a unique digit.