Decimals ka Jod aur Ghataav
Class 7 Maths · Chapter 3: Point ke Aage Ek Jhalak · NCERT Ganita Prakash section 3.7
Seekho
Zoya ko kurte ke liye 2.7 m kapda chahiye aur uski behan ko skirt ke liye 3.5 m. Kul: point ek line mein rakho aur aam tarah jodo: 7 tenths + 5 tenths = 12 tenths = 1 unit aur 2 tenths, haasil 1 → 6.2 m. Antar 3.5 − 2.7: 1 unit ko 10 tenths se badlo: 15 − 7 = 8 tenths → 0.8 m.
2.7 + 3.5 = 6.2 · 3.5 − 2.7 = 0.8
Lambe numbers: 75.345 + 86.691 = 162.036. Thousandths: 5 + 1 = 6; hundredths: 4 + 9 = 13 → 3 likho, haasil 1; tenths: 3 + 6 + 1 = 10 → 0 likho, haasil 1; aise hi aage. Lambaai alag ho to zero lagao: 0.934 + 0.6 = 0.934 + 0.600 = 1.534.
75.345 + 86.691 = 162.036
Decimal sequences: 4.4, 4.8, 5.2, 5.6, 6.0 … har baar 0.4 jodta hai; aage 6.4, 6.8, 7.2. Aur 5, 4.95, 4.90 … har baar 0.05 ghataata hai. Mann mein karke dekho!
4.4, 4.8, 5.2, 5.6, 6.0, 6.4 …
Pehle andaaza: 25.936 + 8.202 ka jod 25 + 8 = 33 (whole hisse) se zyaada par 33 + 2 = 35 se kam, kyunki har decimal hissa 1 se kam hai. Theek jod 34.138 hai, jo fit hota hai. Aisa jaldi ka range galat point jaisi galtiyan pakadta hai.
33 < 25.936 + 8.202 = 34.138 < 35
Explore: jod jaancho.
- Har jod ya antar ko uske jawab se milaao.
Yaad rakho
- Decimal point line mein rakho (zero bharo), phir whole numbers ki tarah jodo ya ghatao.
- Whole hisson se andaaza: jod (whole hisson ka jod) aur (usme + 2) ke beech hota hai.
Quick check
17 − 16.198 = ?
- 0.802
- 1.802
- 0.198
- 1.198
Answer
0.802. 17 = 17.000; 17.000 − 16.198 = 0.802.
Socho
Sabziyan 0.25 kg, 0.3 kg, 0.5 kg, 0.2 kg aur 0.05 kg ki hain. Kul kitna?
Ek answer
0.25 + 0.30 + 0.50 + 0.20 + 0.05 = 1.30 kg. Jode banaao: 0.25 + 0.05 = 0.3, aur 0.3 + 0.5 + 0.2 = 1, to 1.3 kg.
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.