Numbers ke saath maza
Class 6 Maths · Chapter 5: Prime Time · NCERT Ganita Prakash section 5.6
Seekho
Twin primes aise primes hain jinka antar 2 ho: 3 aur 5, 11 aur 13, 29 aur 31. Kisi ko nahi pata ki twin primes hamesha milte rahenge ya nahi. Ye ek aur unsolved paheli hai!
Ye try karo: 4 se aage har even number do primes ka jod lagta hai. 10 = 3 + 7, 20 = 7 + 13, 36 = 17 + 19. Logon ne bahut bade numbers jaanche, par koi prove nahi kar paaya ki ye hamesha sach hai.
10 = 3 + 7 · 20 = 7 + 13 · 36 = 17 + 19
Main kaun hoon? Main 2-digit prime hoon. Mere digits ka jod 7 hai, aur mera dahaai digit ikaai se 1 zyada hai. Aise sanket dheere-dheere jawaab tak le jaate hain. Socho box dekhne se pehle try karo!
Explore: do aise primes chuno jinka jod target ho.
- Do primes tap karo jinka jod 30 ho.
- Naya board: do primes tap karo jinka jod 24 ho.
Yaad rakho
- Twin primes ka antar 2 hota hai (11 aur 13).
- 4 se aage har even number do primes ka jod lagta hai, par koi prove nahi kar paaya.
Quick check
Kaunsa joda twin primes hai?
- 7 and 9
- 13 and 15
- 17 and 19
- 21 and 23
Answer
17 and 19. 17 aur 19 dono prime hain aur antar 2 hai. 9, 15 aur 21 prime nahi.
Socho
Paheli suljhaao: main 2-digit prime hoon, mere digits ka jod 7 hai, aur mera dahaai digit ikaai se 1 zyada hai.
Ek answer
Dahaai + ikaai = 7 aur dahaai = ikaai + 1, to ikaai + 1 + ikaai = 7, yaani ikaai = 3 aur dahaai = 4. Number 43 hai, aur 43 prime hai.
Practice
Teen levels (easy, medium, hard) ke naye sawaalon se practice karo, kuch hands-on, hints aur hal ke saath. Topic poora karne ke liye pichhle 5 mein se 4 sahi karo.