Here is a math trick so unbelievable that it will stump you. It is pretty amazing
1. Grab a calculator. (you won't be able to do this one in your head)
2. Key in the first three digits of your land line telephone number (NOT the area code)
(For 8 digit Tel. Nos. - key in the first four digits of your phone number)
3. Multiply by 80
4. Add 1
5. Multiply by 250
6. Add the last 4 digits of your phone number
7. Add the last 4 digits of your phone number again.
8. Subtract 250
9. Divide number by 2