Class 6 Maths Chapter 5, Prime Time, opens with the ‘Idli-Vada’ multiples game and builds a deep understanding of factors, multiples, prime and composite numbers, the Sieve of Eratosthenes, twin primes, co-prime numbers, prime factorisation and divisibility tests.
What Class 6 Mathematics Chapter 5 Covers
5.1–5.3 Common Multiples, Prime Numbers & Co-prime Numbers uses the Idli-Vada game and Venn diagrams to find common multiples and common factors (5.1), defines prime and composite numbers (with 1 as neither), constructs the Sieve of Eratosthenes up to 100 (25 primes), explores twin primes (5.2), and introduces co-prime numbers (having only 1 as a common factor) (5.3).
5.4–5.6 Prime Factorisation & Divisibility Tests breaks composite numbers into unique prime factors to check divisibility and co-primality (5.4), derives and applies divisibility tests for 10, 5, 2, 4, 8, 9, 3, 6 and 11 (5.5), and explores Anjneya’s and Guna’s number puzzles (5.6).
Exercises in Chapter 5
- Figure it Out exercise sets across every section with step-by-step Chapter Solutions included at the end of the PDF.
- Summary key formulas, visual proofs, and mathematical puzzles.
Read Class 6 Mathematics Chapter 5 Online
More Chapters
- Previous: Chapter 4: Data Handling and Presentation
- Next: Chapter 6: Perimeter and Area
- Hindi medium: Class 6 Maths Chapter 5 PDF in Hindi (Ganita Prakash)
- All Mathematics chapters and the other Class 6 books: Class 6 NCERT books 2026-27
- All Class 1 to 12 NCERT Textbooks: NCERT Books PDF (Class 1–12)
FAQ
Why is the number 1 neither prime nor composite?
A prime number must have exactly two distinct factors (1 and itself), and a composite number has more than two factors; the number 1 has only one factor (itself), so it is neither prime nor composite.
How do you test whether a large number is divisible by 4 and by 8?
A number is divisible by 4 if the number formed by its last two digits (tens and ones) is divisible by 4; it is divisible by 8 if the number formed by its last three digits (hundreds, tens and ones) is divisible by 8.