I know somebody posted the exact formula to this a long time ago. It seems to be substituting different integers but the forumla looks the same on each try.
Think of a number. Add 3 to it. Double the result. Subtract 4. Divide by 2. Subtract the number you first thought of. Add 2. The answer is 3. Want to know how this works? Call the initial number "x" and write out the above sequence of steps in terms of x.
This is NOT esp, it's maths Read up the Trachtenburg system of mathematics some time, you will find an entirely different system of maths that can teach you to being able to do genius...gifted sevant style mathematics in your head in seconds, no written calculations needed. You can do things with numbers you wouldn't think possible based on our current teaching methods. Numbers rock! Maths rocks!
James is correct and I am not sure if he emphasized the trick enough. The trick is in the wording and I'll de-trickify it. 1) Pick a number 2) x = the number you picked 3) y = anything + / - anything 4) z = x - x + y <---- the 'x - x' is the trick as it cancells itself out.
I always find things like these hilarious. I got into an argument with my grandfather once. I was 16 and he kept telling me it was magic when he would do it with me. I freaking did the math and told him his trick would always work out how he wanted it to. I guess he thought I was still 5?
I hear ya, some cheesy math teacher in my past not only touted 1 + 1 <> 2 but actually belived his proof was real: 1x + 1 <> 2 where x is any value but 1. Thats serious redardation right there by jimminy.
If anybody is still wondering, here is is algebraicly: (2(x+3) - 4)/2 - x + 2 = (2x + 6 - 4)/2 - x + 2 = (2x + 2)/2 - x + 2 = x + 1 - x + 2 = 3
