Multiplication of 11 with any number of 3 digits

Let me explain this rule by taking examples

412*11= 4….(4+1)….(1+2)….2 =4532

Means insert the sum of first and second digits, then sum of second and third digits between the two terminal digits of the number
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Here an extra case arises
Consider the following examples for that

1) 429*11=4….(4+2)+1….(2+9-10)---9=4719

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) 768*11= 7+1…(7+6-10)+1….(6+8-10)….8 = 8448