1. VILOKANAM
(BY OBSERVATION)

2. Multiplication
• Multiply number by 10,100,1000
• How?
• 25 x 10 = 250
• Means removing 1 and its zeros are
adjusted on right side of the number.
• Again….
• 65 x 10 = 650
• 98 x 100 = 9800

3. Multiplication with 10,100…
• 200 x 300 = 60000
• Simple……
• 80 x20x5 x 7 = 80 x 100 x 7 =560 x 100
• Answer is …56000
• Another one….
• 17 x 4 x 5 x 10 = 17 x 20 x 10 = 17 x 200
• Answer is …. 3400

4. Multiplication with number 5
• 246 x 5 = 2460/2
= 1230
• 478952 x 5 = 4789520/2
= 2394760

5. Multiplication with 25
• 125 x 25 = 12500/4
= 3125
• 6547 x 25 = 654700/4
= 163675

6. Multiplication with 125
• 125 x 125 = 125000/8
= 15625
• 4587 x 125 = 4587000/8
= 573375

7. Multiplication of two digit
number with 11
• 52 x 11 = 5 (2+5)2 = 572
• 23 x 11 = 2 (2+3)3 = 253
• 11 x 11 = 1 (1+1)1 = 121
• 58 x 11 = 5 (5+8)8 = 638 ( sum is 13,one is
carry forward,5+1 =6)