The Phone number trick

Type in the first three digits of your phone number (not the area code)
Multiply by 80
Add 1
Multiply by 250
Add the last 4 digits
Add the last 4 digits again
Subtract 250
Divide by 2
Recognize the answer?

Its amazing how this works, but all it is is a bit of algebra.

Hard Riddle

Dio's youth lasted for 1/6 of his life. He grew a beard 1/12 more of his life. After 1/7 more of his life , Dio got married. Five years later he had a son. The son lived exactly half as long as his father, and Dio died just four years after his son's death. All of this totals the length of Dio's life.

What was his age when he died?