Monthly Archives: April 2013

If you are planning to buy a good laptop for business, travel, or just at home use, then this is a good PC for you. It’s called the Gateway – 15.6″ Laptop Model NE56R48U. For the duration of this article, it will be referred to as the Gateway PC. This well-rounded computer is 15 inches across and 10 of depth. It is 1.3 inches tall,and is only 5 pounds. Overall, it’s a decent size. The Gateway PC comes with an high definition widescreen, and with an Intel support audio system, also HD. A duel core processor gives this machine enough processing power to run all of your favorite programs. Not only that, but with a maximum of 8 gigabytes of RAM, it can run them at the same time. But the deal doesn’t stop there. The Gateway PC has 2.2 gigahertz, so it surfs the web at a great speed. The 6 cell lithium ion battery lets you go on for hours before you need to plug it into a wall socket. The Gateway PC has 320 gigabytes of storage, so you can save every picture and word document, and every video you record with the built-in webcam. But the best part is that this amazing laptop is only $320! You can buy one here.

chronoChronotron from cool math games is a popular logic game in which players must use past versions of themselves to complete puzzles. In fact, it involves real physics, or at least real theoretical time-travel ideas.

For example, if a player makes it impossible for his past self to return to the time machine and go back to become what he is now, the game paradoxes and the player must start over.

Interesting ideas arise, such as your past self going back in time, thus increasing the amount of you’s on the level.

The game also has physics such as scales, levers, and gates.

Check it out for free at and look for Chronotron.

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Most ciphers you know of are probably static shift-ciphers-that is, where every time you shift you shift exactly the same amount. These can be easy to crack and not very safe codes.

Dynamic Shift-ciphers are where each letter is not necessarily shifted by the same amount. For example, here is the position dynamic shift-cipher.

  1. Take word: “shift this”
  2. s shifts 1, then another one because it is position 1. S becomes U
  3. h shifts 1, then 2 more because it is position 2 becoming k
  4. So forth,
  5. When you reach the second s, it will not be a U again. It will be z, because 1+4(its position in the word)

Other Dynamic Shift-ciphers exist. They are harder to crack because the same letter in the code does not necessarily represent the same letter. Post other ideas in comments:

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[caption id=”” align=”alignright”
DOScommand line, cryptic os that was the first. Windows is built of it.


Unix/Linux – OS with graphical interface but still largely centered on command line.


Windows – first true graphical OS. Based on DOS, with icons, files, and windows.


Os XApple interface, very sleek, icons and windows. Now with Launchpad for a more Application based OS.


iOS – iPhone Os, no file system, true Application Based Os




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Completing the square is an algebra method for factoring. For example:
You have this equation:
x^2 + 4x = -4
You could try to factor the left side, but that would be long and not neat.
What we need to do is complete the square, or modify the equation so it can be factored to a perfect square.

The perfect square we are aiming for is (x+2)^2. What we do to get this is add a certain number to both sides. In this case, since we are aiming for (x+2)^2, the number is 4.

Adding 4 to both sides gives:
x^2 + 4x + 4 = 0

Now we can factor to:
(x+2)^2 = 0

Now all we have to do is solve x+2 = 0 to get

(-2)^2 +4(-2) =-4