Chapter 1: Hamare Aas-paas Bade Numbers
Lakh, crore aur billion hamare aas-paas hain: aabaadi, dooriyon aur record tathyon mein. Is chapter mein hum Indian aur American system mein bade numbers padhenge-likhenge, dekhenge ek number kitne tareekon se banta hai, round aur andaaza karenge, aur bade product ke shortcut aur pattern dhoondhenge.
Is chapter mein tum
- lakh aur crore mein numbers padhna-likhna
- Indian aur American system ke beech badalna
- nearest thousand, lakh ya crore tak round karna aur andaaza lagaana
- shortcut use karna aur product ki lambaai ka andaaza
Topics
- Ek Lakh Kismein! NCERT 1.1
1,00,000 (ek lakh) sabse chhota 6-ank ka number hai: 99,999 + 1.
- Dahaiyon ka Desh NCERT 1.2
Ek number +1, +10, +100… ke click se kai tareekon se ban sakta hai.
- Crore pe Crore! NCERT 1.3
1 lakh = 5 zero, 1 crore = 7 zero, 1 arab = 9 zero; 1 million = 6 zero, 1 billion = 9 zero.
- Theek aur Lagbhag Maan NCERT 1.4
Lagbhag maan aksar kaafi hote hain; kuch cheezein (paise, phone number, davaai) theek honi chahiye.
- Products ke Pattern NCERT 1.5–1.6
× 5 = ÷ 2 phir × 10; × 25 = ÷ 4 phir × 100; × 125 = ÷ 8 phir × 1000.
Key words
- Lakh
- 1,00,000: sau hazaar
- Crore
- 1,00,00,000: sau lakh
- Million
- 1,000,000: das lakh
- Billion
- 1,000,000,000: sau crore (ek arab)
- Round off
- number ko paas ke aasaan number se badalna
- Estimate
- round karke jaldi ka paas ka andaaza
Summary
- 1 lakh = 1,00,000; 1 crore = 1,00,00,000; 1 arab = 100 crore.
- Indian commas 3-2-2-…; American 3-3-3-…; 10 lakh = 1 million, 100 crore = 1 billion.
- Sabse kam click = ankon ka jod; round karne ke liye agla ank dekho (5 ya zyaada → upar).
- × 25 = ÷ 4 × 100; a-ank × b-ank mein a + b − 1 ya a + b ank.