Wednesday, June 27, 2007

Fun with digits

Here is a math trick so unbelievable that it will stump you.

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 phone number (NOT the area code)
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

Do you recognize the answer??


chelene said...

Yes and that was weird because I can't figure out how it happened.

Kevin said...

Just a simple bit shift... 80x250 multiplies the first 3 digits by 20000 and then when you enter the last four twice. You have a number that is double your entered number and then you divide by 2 and viola... there's your number..

Slave to the dogs said...

Chel - you know there's a formula to these things but they break out the steps so that it looks like magic.

People like our friend Kevin can figure that out. :)