Here is why this works:
2. Key in the first three digits of your phone number (NOT the area code)
3. Multiply by 80 4. Add 1
(first three digits * 80) + 1
5. Multiply by 250
((first three digits * 80) + 1) * 250
or
((first three digits * 80) * 250) + (1 * 250)
or
(first three digits * 20,000) + 250
6. Add the last 4 digits of your phone number
7. Add the last 4 digits of your phone number again.
(first three digits * 20,000) + 250 + (last 4 digits * 2)
8. Subtract 250
(first three digits * 20,000) + (last 4 digits * 2)
9. Divide number by 2
(first three digits * 10,000) + (last 4 digits)
555-1234 would work out like this.
(555 * 10,000) + 1234
or
5,550,000 + 1234
or
5,551,234
pseudo