1. Multiplication Trick: Vertically and Crosswise
This method allows you to multiply two-digit numbers quickly
Example: 23 x 45
Step-by-Step:
Multiply the units digits: 3×5=15 (write down 5, carry over 1)
Cross-multiply and add: 2×5+3×4=10+12=22 (add the carry over 1, making it 23, write down 3, carry over 2)
Multiply the tens digits: 2×4=8 (add the carry over 2, making it 10, write down 10)
Result: 1035
2. Squaring Numbers Ending in 5
For any number ending in 5, squaring is straightforward
Example: 752
Step-by-Step:
The last two digits are always 25
Multiply the number formed by the digits before 5 by itself plus one: 7×8=56
Result: 5625
3. Subtraction from 1000
Quickly subtract any three-digit number from 1000
Example: 1000−648
Step-by-Step:
Subtract each digit from 9, except the last digit from 10
9−6=3
9−4=5
10−8=2
Result: 352
4. Multiplying by 11
Easily multiply any two-digit number by 11
Example: 43×11
Step-by-Step:
Split the number into two digits (4 and 3)
Add these two digits together (4 + 3 = 7)
Place the result in between the original two digits
Result: 473