Magic Calculator to determine phone number

[Chernabog]

Originally Posted by DisneyDaniel

Some morning-radio DJs in San Diego talked about this cool thing to try if you're bored or like these kinds of math/number tricks:

Check out this formula to amaze your friends and secretly get their phone number! Just grab a calculator and...

1. Input the first 3 digits of your phone number (NOT the area code)
2. Multiply by 80
3. Add 1
4. Multiply by 250
5. Add the last 4 digits of your phone number
6. Add the last 4 digits of your phone number, again
7. Subtract 250
8. Divide by 2
9. Read the final number aloud for all to hear!

Heh this trick is especially silly since you'd have your friend's phone number at step 5