🔢 Multiplication Short Tricks
1. Multiply by 11 Trick
👉 Rule: Digits को अलग करो और बीच में उनका sum डाल दो।
2. Number ending with 5 का Square (n5 × n5)
👉 Formula: (n5)2=n×(n+1)∣25
3. Multiply by 9, 99, 999... Trick
-
67×99=(67×100)–67=6700–67=6633
-
84×999=(84×1000)–84=84000–84=83916
4. Vedic Maths Trick (For 2-digit numbers close to 100)
👉 Formula: (100–a)(100–b)=100(100–(a+b))+(a×b)
-
Example:
97×96
a=3,b=4
Step 1: 100–(3+4)=93
Step 2: 3×4=12
Answer = 9312
5. Cross Multiplication Trick (2-digit × 2-digit)
👉 Example: 23×47
-
Last digit multiply: 3×7=21 → write 1, carry 2
-
Cross multiply: (2×7)+(3×4)=14+12=26 + carry 2 = 28 → write 8, carry 2
-
First digit multiply: 2×4=8 + carry 2 = 10
Answer = 1081
6. Multiply by 5, 25, 50, 75
-
n×5=(n÷2)×10
👉 468×5=(468÷2)×10=2340
-
n×25=(n÷4)×100
👉 64×25=(64÷4)×100=1600
-
n×50=(n÷2)×100
👉 86×50=(86÷2)×100=4300
-
n×75=(n÷4)×300
👉 36×75=(36÷4)×300=2700
7. Numbers close to 50 (Vedic Style)
👉 Formula: (50+a)(50+b)=2500+50(a+b)+ab
-
Example:
53×48
a=+3,b=–2
Step 1: 2500+50(3–2)+(3×–2)
Step 2: 2500+50(1)–6=2544
Answer = 2544
8. Multiply by 99, 999 in 1 step
👉 Shortcut: Just subtract from 100, 1000...
-
54×99=54×100–54=5400–54=5346
-
73×999=73×1000–73=73000–73=72927
9. Multiply by 125
👉 Formula: n×125=(n×1000)÷8
10. Easy Trick for Double Numbers (Like 23×22, 45×44)
👉 Formula: n(n–1) at end + 2nd digit squared
No comments:
Post a Comment