6
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Below are some matchsticks arranged to display an expression.

Your task is to remove one matchstick so that the resulting value of the expression will be twelve.

enter image description here

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    $\begingroup$ Just to be clear. Remove--- not Move right? $\endgroup$ – DrD Oct 9 at 18:10
  • $\begingroup$ There are so many possibilities... $\endgroup$ – TroyD Oct 10 at 2:25
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    $\begingroup$ I love how many answers the people on this group have come up with to what is essentially an impossible problem! $\endgroup$ – Dr Xorile Oct 11 at 18:04
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    $\begingroup$ There seem to be a lot of different answers here, and no reason to particularly prefer any of them. (Several of the other answers seem more plausible than the accepted one.) $\endgroup$ – Deusovi Oct 11 at 22:09
  • $\begingroup$ @Deusovi Thanks,but I did not accept the answer just because I preferred it. I only accepted it because it was what I had in mind in the first place. $\endgroup$ – ention everyone Oct 12 at 0:47

11 Answers 11

19
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Remove the top of the 7. The 8 can be viewed as 13, so $13-1= 12$. Which also means that you can make it equal to $13-7=6$ without moving any matches!

Demonstration:

enter image description here

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  • 2
    $\begingroup$ "Without moving any matches" yet you had to move two matches to make it work! $\endgroup$ – Weather Vane Oct 13 at 18:22
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    $\begingroup$ Next puzzle: Turn 8 into 13 without touching anything $\endgroup$ – Helena Oct 20 at 16:37
22
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Here is another fairly lateral one:

enter image description here

If we interpret "-" as difference of shapes then the result is a small "c" which is, of course, the hexadecimal for 12.

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    $\begingroup$ difference of shapes, hexadecimal, you seem to have very flexible interpretation of the assignment ;-) $\endgroup$ – TMS Oct 11 at 20:49
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    $\begingroup$ @TMS Don't say flexible, please. I prefer the word "lateral" ;-) $\endgroup$ – Paul Panzer Oct 11 at 22:20
10
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Possibly a little too lateral but if we

Remove the middle match from the '8' to make a '0'

And then

Look at the image inverted

We get

enter image description here

which could be interpreted as

L - 0 = L and since L is position 12 in the alphabet, this can be interpreted to evaluate to 12.

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    $\begingroup$ But, but, but... if the left is an L shouldn't the right be an O (the letter, not the digit)? $\endgroup$ – Paul Panzer Oct 9 at 23:32
  • $\begingroup$ I also had this idea, but usually people would use $A$ for $10$, $B$ for $11$, etc. $\endgroup$ – WhatsUp Oct 9 at 23:33
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    $\begingroup$ @WhatsUp Actually, my first inclination would be that L=50 $\endgroup$ – hexomino Oct 9 at 23:34
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    $\begingroup$ @PaulPanzer Nah man, it's clearly a 0. $\endgroup$ – hexomino Oct 9 at 23:35
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    $\begingroup$ Actually, the more I think about it the more I like it. The "-0" does a decent job of killing the L=50 association. This almost resembles something intentional ;-) $\endgroup$ – Paul Panzer Oct 10 at 0:22
6
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A bit of a stretch, but here goes:

enter image description here

The only way to read the thing on the left as a number is as a 1 and a 9 who haven't heard about social distancing rules. So that will read 19-7.

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  • $\begingroup$ It just looks like an "A" to me $\endgroup$ – bobble Oct 9 at 23:00
  • $\begingroup$ @bobble Just squint a bit ;-) --- I said it was a bit of a stretch. And I wouldn't have posted this if the other answers were any more compelling. $\endgroup$ – Paul Panzer Oct 9 at 23:04
  • $\begingroup$ So your final result is $3$... Also you don't have to remove any stick to read it as $19$. $\endgroup$ – WhatsUp Oct 9 at 23:11
  • $\begingroup$ @WhatsUp The point is that with the bottom in place there is no reason at all to read it as anything but an 8. With the stick removed I can't think of any plausible way of reading this as a number other than the one I suggest. $\endgroup$ – Paul Panzer Oct 9 at 23:18
  • $\begingroup$ You could read it as "1 - 7" just as easily as "19". $\endgroup$ – chepner Oct 10 at 18:47
4
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My answer is

Invert the image
Remove the match which is (now) bottom right

enter image description here

This leaves two characters L and @
In ASCII encoding, the difference in their values is $12$

Similar to other answers, but "sticks" to a single coding scheme.

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3
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Remove the lower-left stick on 8. enter image description here

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0
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Japanese borrowed the English word dozen as ダース (dāsu). Remove the bottom left match and you get:

_ _ |_| _ | | | |

which is ダース in a rather crappy low resolution font (especially the su is really ugly)

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    $\begingroup$ That can by no means be read as a ス. Anybody would rather call it a フ. Also you are missing the two dots, which are crucial. So basically you created a ターフ $\endgroup$ – WhatsUp Oct 9 at 19:52
  • $\begingroup$ @RadovanGarabik Cool! $\endgroup$ – ention everyone Oct 9 at 19:55
0
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My swing at it:

Remove the middle bar from the 8. It’s now D hexadecimal. Minus 1 is C which is 12 base 10.

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0
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In very lateral thinking, let "remove one matchstick" be interpreted as "re-move one matchstick", which means to move one matchstick again. So move the top right matchstick to the windowsill. Then re-move it to the middle of the puzzle so it reads B + 1, which in hexadecimal is 11 + 1, which is 12.

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-1
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Remove the middle stick on the left. Then you get "0 - 7" which equals 12 (mod 19).

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  • $\begingroup$ Can't understand how this is correct if we are taking mod $19$ like that way. $\endgroup$ – Anonymous Oct 11 at 4:29
  • $\begingroup$ @Anonymous Minus seven is congruent to twelve mod 19. $\endgroup$ – Rand al'Thor Oct 11 at 6:45
  • $\begingroup$ It is, but why are we considering mod? in that case I would solve most of the matchstick problems like this, taking mod of a certain number, in this case, 19 $\endgroup$ – Anonymous Oct 11 at 8:57
-2
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Move a stick from 8 and place it over '-' to make a '+'. enter image description here

Next remove a stick as shown to get 5+7=12. enter image description here

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    $\begingroup$ If you are are allowed a preprocessing step, you could simply rearrange the matchsticks all you like before removing one. $\endgroup$ – chepner Oct 10 at 18:48

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