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Move one matchstick to make an equality.enter image description here

Question made by me (Is this too easy?)

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Culver Kwan
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  • First idea was: 9 - 5 < 5. But I believe your request of an equality wouldn't allow this inequality. – Swiss Frank Jun 03 '20 at 09:07
  • @SwissFrank: To be honest I would also count that as requiring two moves, one for each of the = matches since you need to rotate both. – Flater Jun 03 '20 at 10:50

7 Answers7

54

Another solution:

Interpreted in hexadecimal: A-5=5

tmpearce
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Scott Miller
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47

Here's one way:

enter image description here

For the image-impaired:

5 = 5 = 5

tmpearce
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    Correct! I was thinking about this answer! – Culver Kwan Jun 01 '20 at 02:27
  • Congrats! You earned Enlightened, Good answer and, Nice answer for answering this question! – Culver Kwan Jun 02 '20 at 05:00
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    Technically, that is not "a correct equation", but rather, a few correct equations... – João Mendes Jun 02 '20 at 13:12
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    But the two = signs are not at the same height... I dismissed this solution in my mind, since I'd have to move two matchsticks to make the = match the other =. @ScottMiller's solution should be the accepted answer, since it is truly moving only one matchstick to make an equality (although, it's definitely not "easy"!). – LHM Jun 03 '20 at 21:20
33

Another solution is to

move the center bar of the 9 to the lower left position of that digit to make a 0

and then

look at it from the other side of the table (i.e. rotate it 180 degrees), so it appears to say $5=5-0$

shoover
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    Isn't doing the second part of that equivalent to moving all of the match sticks? – Kevin Jun 01 '20 at 22:34
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    Not if they're on a flat table. – shoover Jun 02 '20 at 01:31
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    @KevinWells: It depends on how much the puzzle constrains lateral thinking. Free rotations is usually not in the spirit of these puzzles but I wouldn't blanket exclude lateral solutions either as they are an interesting style in and of themselves. – Flater Jun 03 '20 at 10:51
  • @Flater I would expect that kind of question to include the lateral thinking tag, but I get that some people prefer to look at all puzzles through that lens – Kevin Jun 03 '20 at 18:40
10

One more possibility:

Move the upper-left stick of the 9 to cross the equals sign so we get 3 - 5 ≠ 5

Phin Jensen
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5

This is the first thing that came to mind (when the question was originally posed as "Move one matchstick to make an equation"):

enter image description here

Written out:

5 - 5 ≠ 5

Derek O
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    Wait, your picture is different from your written out answer! – Culver Kwan Jun 02 '20 at 01:48
  • Seems like you notice the word “equality”. You formed an inequality. – Culver Kwan Jun 02 '20 at 03:16
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    @CulverKwan: I don't see the word "equality". I see the word "equation". I've always considered inequalities to be equations, as you can still manipulate them using the same rules. Most of the internet seems to agree with you, but if I've ever heard this distinction, I don't remember it. My concept was to move the bottom bar of the 9 to form a not-equals sign, and there's another version elsewhere, so apparently at least 3 people on Earth think of this as an equation. – MichaelS Jun 03 '20 at 02:12
  • @MichaelS, I will edit the question. – Culver Kwan Jun 03 '20 at 02:13
3

You can also make it:

9-4=5

just by

moving the top match from the first 5

F1Krazy
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JustZig
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    You would need to move the bottom one too. – rtaft Jun 02 '20 at 14:29
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    It would still be readeable with the bottom one there, at least in my opinion. I think there are a bunch of answers to this. – JustZig Jun 02 '20 at 14:38
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    It may still be readable but IMO the "4" with a bottom bar is not a number. When have you ever seen a 4 drawn with a bar on the bottom? – mittmemo Jun 02 '20 at 21:13
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    https://image.freepik.com/free-photo/woman-s-hand-holding-up-number-4-against-yellow-background_23-2148188526.jpg – JustZig Jun 03 '20 at 13:14
-1

I'm not familiar with the process by which y'all are rendering these (some type of MatchstickML based on TeX and MathJax?) But as there is no specified alignment and you assume they may only be vertical or horizontal, if you move the \U+002D matchstick to the initial 9, one could consider that that a crossed or dotted zero, (as all zeros should be), leaving something akin to

0̸５＝

(Something akin to padding a simple 8-bit decimal in UTF-16 with a BOM, for ridiculous encodings like that.

P.S. I'm honounered to be Lizzy, but where's Colonel Brandon?

Elizabeth Bennet
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  • No, it is to complicated. – Culver Kwan Jun 03 '20 at 00:51
  • "I'm not familiar with the process by which y'all are rendering these (some type of MatchstickML based on TeX and MathJax?)" These are all just plain old images, created probably with something like Paint. – zovits Jun 03 '20 at 13:00