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Excel 2007 Multiplication Bug

Posted by kdawson on from the be-fruitful-and-all-that dept.

tibbar66 writes with news of a serious multiplication bug in Excel 2007, which has been reported to the company. The example that first came to light is =850*77.1 — which gives a result of 100,000 instead of the correct 65,535. It seems that any formula that should evaluate to 65,535 will act strangely. One poster in the forum noted these behaviors: "Suppose the formula is in A1. =A1+1 returns 100,001, which appears to show the formula is in fact 100,000... =A1*2 returns 131,070, as if A1 had 65,535 (which it should have been). =A1*1 keeps it at 100,000. =A1-1 returns 65,534. =A1/1 is still 100,000. =A1/2 returns 32767.5."

51 of 806 comments (clear)

  1. Microsoft just announced plans for their fix by Anonymous Coward · · Score: 5, Funny

    They will be disabling multiplication in all future versions of Excel.

    1. Re:Microsoft just announced plans for their fix by cloricus · · Score: 5, Funny

      It is nice to see that since this is a free and open standard that the bug has been identified quickly and fixed.

      Oh wait, it isn't and the bug is still at large. Sorry, jumped the gun there due to the speed at which the Open Source community usually fixes issues like this. Maybe ISO should take note.

      --
      I ate your fish.
    2. Re:Microsoft just announced plans for their fix by Waffle+Iron · · Score: 5, Funny
      Microsoft already has a patch in the works to help users overcome this issue. Whenever the user types a '*' in a formula, an animated sprite of Charles Babbage's head will pop up. It will show this bubble caption:

      "It looks like you're trying to multiply two numbers. I can help show you how to use the Method of Finite Differences to find a good approximation of your answer using only addition and subtraction. Would you like me to bring up a wizard so that we can get started on finding an appropriate power series?"

    3. Re:Microsoft just announced plans for their fix by Bionic+Vapour+Boy · · Score: 4, Funny

      This doesn't work either: =850/(1/77.1) So they have to disable the divide-operation altogether.

    4. Re:Microsoft just announced plans for their fix by jkrise · · Score: 5, Funny

      They will be disabling multiplication in all future versions of Excel.

      No, no, no... remember this is effectively Office Vista.. so the fix will be, like:

      You are trying to multiply 2 numbers and the answer is 65535. This is a very dangerous multiplication frequently used in viruses... Cancel / Allow?

      --
      If you keep throwing chairs, one day you'll break windows....
    5. Re:Microsoft just announced plans for their fix by Chainsaw · · Score: 5, Funny

      Windows 4: "Oh, man. The previous one was garbage, but this one is making me physically ill."
      Windows 5: "What the hell have you done? Delete it! Delete it!"
      ...
      Windows 95: "Fuck it, we have to release this steaming pile of crap now.

      Just a theory...

      --
      War is one of the most horrible things a human can be exposed to. And one of the worlds largest industries.
    6. Re:Microsoft just announced plans for their fix by edittard · · Score: 4, Funny

      What you need is specialised hardware.

      --
      At the bottom of the /. main page it says 'Yesterday's News'. Well they got that right.
    7. Re:Microsoft just announced plans for their fix by nschubach · · Score: 5, Funny

      Maybe the mod points are being run through Excel before being applied to posts.

      --
      Every time I start to have faith in humanity, I ruin it by driving to work between 7 and 8 am.
    8. Re:Microsoft just announced plans for their fix by CarpetShark · · Score: 5, Funny

      You are trying to multiply 2 numbers and the answer is 65535. This is a very dangerous multiplication frequently used in viruses... Cancel / Allow?


      Oh, is that how it works? I thought it wouldn't show you answers above 255, unless you have a HDCP-compliant monitor.
  2. In OOXML? by gvc · · Score: 4, Funny

    Perhaps this is how multiplication is done in OOXML. They do leap years in dates wrong, too.

    1. Re:In OOXML? by mennucc1 · · Score: 5, Funny

      Perhaps this is how multiplication is done in OOXML. They do leap years in dates wrong, too. oh my, it is clearly spelled on page 890 of the draft:
      to retain backward compatibility with MSDOS 16bit mode, the operands of any multiplication that may exceeds a 16 bit boundary must be converted to farsi and multiplied using an abacus emulator, as per sec (II)par alpha comma 2; the result may or may not appear in Windows Genuine Octal Format (a.k.a. fake octal - that is octal without the leading zero and minus 1) for added convenience of EndUser(tm).
    2. Re:In OOXML? by Baricom · · Score: 5, Funny

      I say we petition Microsoft to include a multiplyLikeExcel2007 element in the next version of OOXML.

    3. Re:In OOXML? by Anonymous Coward · · Score: 5, Funny

      The OOXML specs are already 65498 pages long. If Microsoft can give "multiplyLikeExcel2007" a 37 page treatment in the OOXML specs, the total page count for OOXML will reach an amazing 100000 pages (therefore 166 times better than ODF). Sounds like a winning plan to me!

  3. Pentiums by MyLongNickName · · Score: 5, Funny

    What happens if you use this on an older Intel chip? Do the issues cancel out?

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    1. Re:Pentiums by 644bd346996 · · Score: 5, Funny

      Perhaps. I tried to test it out, but the hard drive with the swapfile caught fire before Excel finished loading.

    2. Re:Pentiums by Fuji+Kitakyusho · · Score: 5, Funny

      Not quite. The cell in that case just reads 99,999.999998263, when it should be 65,534.99994721.

  4. Who are you going to call? by renegadesx · · Score: 5, Funny

    1 2 3 4 5 5 6 7 8 9 10 11 12... ...65,533 65,534 100,000

    Give em a break, even the Count from Sesame Street cant count that high.

    --
    Make SELinux enforcing again!
    1. Re:Who are you going to call? by dvonhand · · Score: 5, Funny

      Who are you going to call?

      Ghostbusters?
    2. Re:Who are you going to call? by AJWM · · Score: 5, Funny

      1 2 3 4 5 5 6 7 8 9

      But I think the Count can manage to count to six without stuttering.

      --
      -- Alastair
    3. Re:Who are you going to call? by rubycodez · · Score: 4, Funny

      if you were a real fan you'd know that's when the Counts repeats a number and then comments how wonderful the items being counted are. e.g. five...five *wonderful* vampire bats! mwuhahahahaha!

    4. Re:Who are you going to call? by halcyon1234 · · Score: 5, Funny
      No, dude, you have it wrong. The Count always stops to repeat every now and then, to remind you of the objects being counted.

      1... 2... 3... 4... 5... 5 Mod points for Halcyon! {thunderbolt, lightning, kid-friendly-maniacal laughter}

      --
      UTF-8: There and Back Again
    5. Re:Who are you going to call? by OverflowingBitBucket · · Score: 3, Funny

      1 2 3 4 5 5 6 7 8 9

      But I think the Count can manage to count to six without stuttering.

      Geez, way to go. Give 'em a chance to fix their current problems before you start finding new ones. ;)

  5. It only gets worse. by The+Earl+of+Sandwich · · Score: 5, Funny

    Try =6*9.

    1. Re:It only gets worse. by $RANDOMLUSER · · Score: 5, Funny

      Try =6*9.
      6 * 9 = 42
      What's your point?
      --
      No folly is more costly than the folly of intolerant idealism. - Winston Churchill
    2. Re:It only gets worse. by MostAwesomeDude · · Score: 4, Funny

      So this means that Microsoft is the fundamental flaw in the universe? ...Okay, I'm convinced.

      --
      ~ C.
  6. Vista Sales by xs650 · · Score: 4, Funny

    It's used in the algorithm that MS uses to report Vista sales.

  7. Re:Oh no! by renegadesx · · Score: 5, Funny

    This just in: Florida plans to do use Microsoft Excel to calculate the 08 election results.

    News at 11

    --
    Make SELinux enforcing again!
  8. I can see the OOXML tag now... by mad.frog · · Score: 5, Funny


            =850*77.1
    </MultiplyLikeExcel2007>

    1. Re:I can see the OOXML tag now... by Anonymous Coward · · Score: 5, Funny

      That profoundly uninsightful post (but funny) will probably get modded as insightful.

      Lets wait and see :-)

    2. Re:I can see the OOXML tag now... by fractoid · · Score: 3, Funny

      And your rather funny (but not insightful) post will get modded as... bah, nevermind. :P

      --
      Rampant carbon sequestration destroyed the Dinosaurs' tropical paradise. I'm here to help repair the damage.
    3. Re:I can see the OOXML tag now... by l0b0 · · Score: 5, Funny

      That ... *Head explodes*

  9. Unnecessary abstraction by mikvo · · Score: 5, Funny

    Multiplication is an unnecessary abstraction anyway. This should really be represented by summing the value of 77.1 entered independently into 850 cells: =sum(a1:a850).

    1. Re:Unnecessary abstraction by Rick+Genter · · Score: 5, Funny

      I'd prefer to put 850 in 77.1 cells and do =sum(a1:a77.1)

      --
      Don't underestimate the power of The Source
  10. Retro by starfishsystems · · Score: 3, Funny

    I always said that Microsoft would never successfully migrate from 16 to 32 bits...

    --
    Parity: What to do when the weekend comes.
  11. Re:Dunno... by Ford+Prefect · · Score: 5, Funny

    My copy of excel 200 on Win2k gave the correct result.

    What, lxvDXXXV?

    (And yes, what have the Romans ever done for us, apart from apparently producing correctly functioning spreadsheet software?)
    --
    Tedious Bloggy Stuff - hooray?
  12. Re:Is anyone using Excel 2007? by QuantumG · · Score: 4, Funny

    Of course you did. You don't think they're going to pay you to do bug testing for them do you?

    --
    How we know is more important than what we know.
  13. This is why OOo Calc can never replace Excel by swillden · · Score: 5, Funny

    This is yet another example of where Calc fails utterly to be compatible with Excel. How can I use Calc if I can't be sure that it will produce the same answers that my boss gets with Excel?

    All those open source developers just don't get it. Geeks that they are, they prize accuracy over consistency and uniformity. The clueless dweebs need to get out of their parents' basements and get a clue about how the REAL WORLD works. Nobody gets promoted for contradicting their boss, duh.

    Nope, until Calc can faithfully reproduce every Excel calculation, it simply won't be ready for use in the real world.

    --
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  14. Pay Day! by johkir · · Score: 3, Funny

    Now how can I work this into my salary.......

    --
    These are some of the things molecules do...... given 4 billion years -Carl Sagan
  15. Re:But the important question is.. by Tablizer · · Score: 5, Funny

    Does the built-in flight simulator still work?

    As long as you stay below 65535 feet.

    --
    Table-ized A.I.
  16. Re:So? by eggfoolr · · Score: 5, Funny

    Was it not Bill himself who said you would never need more than 64K of memory? Well it's official, you don't need any number greater than 64K either!

    Just remember Micro$oft knows best... move along, nothing to see here.

  17. The renewal form, hmmm? by NotQuiteReal · · Score: 5, Funny

    And you didn't balk at the 34% increase in rent?

    --
    This issue is a bit more complicated than you think.
  18. Step 2 Found! by OverflowingBitBucket · · Score: 5, Funny

    Well, I'm off to deposit $655.35 less my current balance into my bank account.

  19. Re:Wow... by Kreigaffe · · Score: 5, Funny

    a spot-on analogy involving jedis? you sir win two internets.

    --
    ... still waiting for this free-as-in-beer free beer I keep hearing about. :|
  20. I've got a theory... by XNormal · · Score: 3, Funny

    It must be bunnies!

    --
    Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.
  21. Re:I have another theory entirely. by gogodidi · · Score: 5, Funny

    Unless somebody here works for Microsoft who has access to inside information... I'm sure there are hundreds of you, all those anonymous cowards are probably Microsoft employees in disguise!

    --
    ugh...
  22. Re:I have another theory entirely. by Anonymous Coward · · Score: 5, Funny

    no, I've asked guys around the office; nobody reads slashdot here.

  23. Re:Oblig. by Stealth+Potato · · Score: 4, Funny

    The number 65,536 is an awkward figure to everyone except a hacker, who recognizes it more readily than his own mother's date of birth
    Oh god. I never even realized until this very moment that this was true. I feel like a horrible person. ;_;
  24. Re: Your sig by Dolda2000 · · Score: 5, Funny

    sed 's/readSlashDot\(\)/meetWomen\(\)/g' braindump.txt Oh please! Everyone knows that sed uses old-style regexes, where `\(' and `\)' are subpattern delimiters, not literal parentheses. Furthermore, you'd never need to escape parentheses in the replacement part of the command (unless, of course, you use parentheses as command part delimiters).

    No wonder you can't meet any women!

  25. Re:Is anyone using Excel 2007? by Sam_Brightman · · Score: 5, Funny

    "most numbers seem to multiply ok"

    perhaps making a statement like this about a spreadsheet is not really a shining endorsement. let me know when you've tested the rest of them.

    --
    sam brightman
  26. Re:Oh no! by Slightly+Askew · · Score: 3, Funny
    As a general rule, if you're going to call someone out in public, it's best to check and make sure you're not retarded first.

    I checked, I'm not.

    --
    Public use of any portable music system is a virtually guaranteed indicator of sociopathic tendencies. -- Zoso
  27. Re:Pido libro de reclamaciones por daños. by jandrese · · Score: 5, Funny

    Wow, that was a lot of work to demonstrate that a number ending in a 5 isn't prime.

    --

    I read the internet for the articles.