A Mathematical fun

1) Take a ten digit no, say your mobile no.
2) Take the first 6 digits from left
3) Multiply by 80.
4) Add 1
5) Multiply by 250.
6) Add the no. made by last 4 digits from left.
7) Again add the no. made by last 4 digits from left.
8) Subtract 250
9) Divide by 2
10)Try to recognize the no. Any relation with the no. u chose???
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Can you modify the trick for any 8 digit no ??? Or a 6-digit no ???