# 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

## Step 1: 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.
tech-king7 years ago
i won! beat this: I'm thinking about a number between 0 and 1000. Try to guess it ! You said : 500? My number is lower ! You said : 243? Congratulations ! You won ! You found my secret number in 1 tries. Your score is : 1000 (Press Reset to start a new game.)
coolz (author)  tech-king7 years ago
prove it! post a picture
7 years ago
will do.
coolz (author)  tech-king7 years ago
ok. but someone beat that already. you cant beat him because he got the maximum score already
7 years ago
what if i hack?
coolz (author)  tech-king7 years ago
1. that will get you disqualified 2. hacking wont help
6 years ago
it helps! type this into address bar: javascript:alert(random_number); works in firefox and konqueror.
6 years ago
I'm thinking about a number between 0 and 1000. Try to guess it ! ---> javascript:alert(random_number); <--- ---> new window opens: 656 <--- You said : 656? Congratulations ! You won ! You found my secret number in 0 tries. Your score is : Infinity (Press Reset to start a new game.)
tech-king7 years ago
game didnt work! it wouldnt display fractions, decimals or exponents. I'm thinking about a number between 0 and 1000. Try to guess it ! You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN? You said : NaN?
coolz (author)  tech-king7 years ago
its not supposed to display those things
7 years ago
you mean it wont do fractions, exponents, roots, algebra or basic expressions? lowzy game.
coolz (author)  tech-king7 years ago
no, its a game, not a homework machine
7 years ago
its not a smart program.
coolz (author)  tech-king7 years ago
6 years ago
i know a neuronal net coded in html!
7 years ago
thus its a dumb program. it should freeze up at math.
coolz (author)  tech-king7 years ago
its a game
7 years ago
and a dumb one at that
coolz (author)  tech-king7 years ago
i didnt even make the game! if you're gonna complain, complain to chooseausername
zimmemic256 years ago
i needed 10 tries. the ****ing number was 559!!! how should someone guess it??? LOG: I'm thinking about a number between 0 and 1000. Try to guess it ! You said : 500? My number is greater ! You said : 750? My number is lower ! You said : 700? My number is lower ! You said : 600? My number is lower ! You said : 550? My number is greater ! You said : 560? My number is lower ! You said : 555? My number is greater ! You said : 556? My number is greater ! You said : 557? My number is greater ! You said : 558? My number is greater ! You said : 559? Congratulations ! You won ! You found my secret number in 10 tries. Your score is : 100
n8man7 years ago
Coolz really left!
mrmucox7 years ago
I win!
coolz (author)  mrmucox7 years ago

## NEW RECORD HOLDER!

congrats! you have the record forever because that was the maximum possible score!
7 years ago
Looks like he hacked look at the one of the person who hacked.
7 years ago
Ummm... no. You'll notice it's 500, my first guess. Anyone's first guess.
7 years ago
I just said that because I lost. No hard feelings.
n8man7 years ago
What is your highest score, mine is 200. (on my second try) You also have it wrong at the third step. You divide the difference of the higher and lower number and add/ subtract it to the last number you guessed and continue doing that until you get the number choosing either the higher or lower when the difference is odd. Good instructable though, it displays the best way to crack this puzzle.
gamer7 years ago
Where is the link to the game??! Very nice technique, but if would be nice to have a link to the game. Thanks. -gamer
coolz (author)  gamer7 years ago
7 years ago
Sorry, I missed it.
Lithium Rain7 years ago
Thats...kind of self evident...
Yes =o)
The "half way" method is the best method to make a great score with this game =o)

Like an old and wise philosopher from the ancient times once told to his young apprentice : «My Little Grasshopper, never forget that the middle path is the way to go, because it stands exactly between the path of the Dark Force of the Empire, and the path of the Crazy Force of Sponge-Bob.»
7 years ago
An old and wise philosopher from ancient named Confusious also once said - He he fishes in another mans well, ends up catching crabs. Nice instructable :P My record was 9 so far
nf1197 years ago
Reminds me of the binary search in computer science.
7 years ago
It does, although this isn't a completely rigorous binary search. I'm still trying to find a concise way of describing binary search in text- the closest I can find is "guess half way between yoru known upper and lower boundaries, then update your boundaries and guess again". I've got a half-finished Instructable about binary search, actually....
7 years ago
Just so. With a true binary search (guessing halfway between the upper and lower bounds each time), you should be able to find a number between 1 and 1000 in 10 tries, rather than 15.
Keith-Kid7 years ago
Haha!
Keith-Kid7 years ago
Nice! I never knew that. I gave it a 4.