metadata
source: ncert
topic: arithmetic
class_level: class_7
chapter: ch2
difficulty: beginner
Class 7 | Ch2: Fractions and Decimals Multiplication of fractions: (a/b)×(c/d)=ac/bd. Convert mixed to improper first. 2(3/4)×1(1/3) = (11/4)×(4/3) = 44/12 = 11/3 = 3(2/3). Division: a/b ÷ c/d = a/b × d/c (multiply by RECIPROCAL of second). 3(1/2)÷1(2/3) = (7/2)÷(5/3) = (7/2)×(3/5) = 21/10 = 2.1. Decimal multiplication: count total decimal places. 0.4×0.3=0.12 (1+1=2 places). Division by decimal: 2.4÷0.6 = 24÷6 = 4 (multiply both by 10). Conversion: 0.125=125/1000=1/8. 1.625=1625/1000=13/8=1(5/8). Common mistake: flip SECOND fraction not first when dividing fractions.