---
source: ncert
topic: numbers
class_level: class_7
chapter: ch9
difficulty: beginner
---

Class 7 | Ch9: Rational Numbers
Rational: p/q where p,q integers and q≠0. Every integer=rational(n=n/1).
Standard form: q>0 and HCF(p,q)=1. So -6/4=-3/2.
Comparison: convert to same positive denominator, compare numerators.
-3/5 vs -2/3: LCM=15 → -9/15 vs -10/15 → -3/5>-2/3.
Dense: infinite rationals between any two rationals.
Operations: p/q+r/s=(ps+qr)/qs. Division: (p/q)÷(r/s)=ps/qr.
Finding rationals between 1/4 and 1/2: between 2/8 and 4/8 → 3/8, 5/16, 7/16.
-3/5+2/3=(-9+10)/15=1/15.
Denominator must be POSITIVE in standard form. -2/3 is greater than -1 (closer to zero).