Here is a mathematical trick so unbelievable you will realize at the end.
1) Grab a calculator. (You wont be able to do this my memory)
2) Key in the first three digits of your phone number if ur phone number is 7 digits or else take the first 4 digits of ur number if its 8 digits.(only land line no.) (Without the area code)
3) multiply by 80
4) Add 1
5) multiply by 250
6) Add the last four numbers of your phone number
7) Add the last four numbers of your phone number again
8) Subtract 250
9) Divide number by 2
Can you recognize the answer?
Don't get confused. This is very simple, just think of the calculations u'll get it.