MULTIPLICATION OF ANY TWO NUMBERS, LIES BETWEEN 11 AND 19
Let me explain this rule by taking examples:
13*19 = (13+9)*10 + (3*9) = 220 + 27 = 247
Means add first number and last digit of the second number take zero in the third place of this number then add product of last digit of the two numbers in it.
EXAMPLE: 18*14 = (18+4)*10 + (8*4) = 220 + 32 = 252
MULTIPLICATION OF 11 WITH ANY NUMBER OF 3 DIGITS.
Let me explain this rule by taking examples:
1. 352*11 = 3---(3+5)---(5+2)---2 = 3872
Means insert the sum of first and second digits, then sum of second and third digits between the two terminal digits of the number
2. 213*11 = 2---(2+1)---(1+3)---3 = 2343 EXAMPLE. Here an extra case arises
Consider the following examples too:
1) 329*11 = 3--- (3+2) +1--- (2+9-10) ---9 = 3619
Means, if sum of two digits of the number is greater than 10, then add 1 to previous digit and subtract 10 to the associated digit.
2) 758*11 = 7+1---(7+5-10)+1---(5+8-10)---8 = 8338
Let me explain this rule by taking examples:
13*19 = (13+9)*10 + (3*9) = 220 + 27 = 247
Means add first number and last digit of the second number take zero in the third place of this number then add product of last digit of the two numbers in it.
EXAMPLE: 18*14 = (18+4)*10 + (8*4) = 220 + 32 = 252
MULTIPLICATION OF 11 WITH ANY NUMBER OF 3 DIGITS.
Let me explain this rule by taking examples:
1. 352*11 = 3---(3+5)---(5+2)---2 = 3872
Means insert the sum of first and second digits, then sum of second and third digits between the two terminal digits of the number
2. 213*11 = 2---(2+1)---(1+3)---3 = 2343 EXAMPLE. Here an extra case arises
Consider the following examples too:
1) 329*11 = 3--- (3+2) +1--- (2+9-10) ---9 = 3619
Means, if sum of two digits of the number is greater than 10, then add 1 to previous digit and subtract 10 to the associated digit.
2) 758*11 = 7+1---(7+5-10)+1---(5+8-10)---8 = 8338
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