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How to guess the mystery number in guessing games

So, a friend just challenged you to think of a number between 1 and 1000, huh? Well, here's a simple way to guess the number without guessing random numbers.

Thanks to chooseausername for giving me the game
 
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Step 1: Half of what?

Picture of Half of what?
Ok, so your number is big. Like, big as 1000. Well, you don't just guess a random number. You say the number that's half of 1000. Well, how do you figure that out? You shrink the number down, of course! Take the numbers after the second digit down, leaving you with 10. Whats half of 10? 5, of course! After that, add the zeros you took off the 10 to the 5, making it 500.

Step 2: What if the number is wrong?

Picture of What if the number is wrong?
Ok, so 500 was wrong. That is to be expected, though. In this case the number is greater, so you have to know what's half of 500 and add it. If the number was lesser, you'd just have to know what's half of 500 and guess from there. So, half of 500 is 250. Then you add 250 to 500, which is 750.

Step 3: Still wrong?

Picture of Still wrong?
Ok, so the number is lower. You can't divide the number by half because it's greater than 500. So, you must go down by 50, making the number 700.

Step 4: Narrow it down...

Now, we know the number is greater than 700, but less than 750. So, you guess half of 50 plus 700 which is 725. However, the number is lower, so we guess 5 down, which is 720. The number is still wrong, so we go 10 down, making the number 710. The number was correct, but if it wasn't, it would tell you if it was greater or less, so you would add or subtract 5, and work from there. This time, I only had to guess 5 times, which is a record, but it may take up to 15 tries if you use this method.

Oh, if you want to practice this method, you can play it here.

Thanks for viewing!
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