Puzzles, Trivia, etc.

[sickness]

This math trick intrigued me so much I figured I'd start a thread dedicated to it and other puzzles and the like so if you've got one, drop it in here.

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 by 2.

Do you recognize the answer?

[Bark]

This math trick intrigued me so much I figured I'd start a thread dedicated to it and other puzzles and the like so if you've got one, drop it in here.

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 by 2.

Do you recognize the answer?

Simple algebra, my man.

Say the first three digits of your phone number are "n" and the last four digits are "y".

It works out to a formula like this:

[250(80n + 1) + y +y - 250]/2

=

[250(80n + 1) + 2y - 250]/2

=

(20,000n + 250 + 2y - 250)/2

=

(20,000n + 2y)/2

=

10,000n + y

So, if your phone number was 123-4567, n=123 and y=4,567. You would be taking:

10,000*123 + 4,567 = 1,230,000 + 4,567 = 1,234,567

Of course, that's your phone number: 123-4567

Isn't math fun!

:D

[Trazalca]

This one I came across was pretty cool.

Go to this website - Mystical Ball (http://www.mysticalball.com/)

Here's the site instructions:

Choose any two digit number. Add together both digits, then subtract
the total from your original number.

So, if you chose the number 23, you'd take the digits 2 and 3,
add them to make 5, you subtract 5 from 23 to get 18.
Find out the symbol next to the number 18, then click the "crystal ball"
the dude is holding, and the symbol appears in the ball!

It took me a few minutes but I figured out the trick.

This deals with the magical qualities of the number 9.
No matter what two digit number you chose, if you followed
the formula listed above, you'll always get a number divisible by 9.
Because of this, you'll quickly notice that ALL of the numbers that
are divisible by 9 share the same symbol. And if your click on the
crystal ball for the symbol, then click on the link to "try again?",
the chart refreshes to different symbols, but you'll always see the same
symbol attached to a number divisible by 9. Making you think it read
your mind. And that's the trick to that.

:rolleyes: