Excel 2007 Multiplication Bug

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."

Comments

Microsoft just announced plans for their fix

[Anonymous Coward]

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

Re:Microsoft just announced plans for their fix

[KUHurdler]

Maybe this is just simplifying the answer to life, the universe and everything. http://en.wikipedia.org/wiki/The_Answer_to_Life,_the_Universe,_and_Everything

Re:Microsoft just announced plans for their fix

[cloricus]

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.

Re:Microsoft just announced plans for their fix

[Waffle Iron]

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?"

Re:Microsoft just announced plans for their fix

[Bionic Vapour Boy]

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

Re:Microsoft just announced plans for their fix

[jkrise]

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?

Re:Microsoft just announced plans for their fix

[Chainsaw]

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...

Re:Microsoft just announced plans for their fix

[edittard]

What you need is specialised hardware.

Re:Microsoft just announced plans for their fix

[nschubach]

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

Re:Microsoft just announced plans for their fix

[CarpetShark]

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.

Re:Microsoft just announced plans for their fix

[mdwh2]

I'm similarly amused by the lack of Mac OS X 1-9; or alternatively, the lack of Mac OS I-IX.

I look forward however to Mac OS X 11, or will it be Mac OS XI 11?

Re:Microsoft just announced plans for their fix

[Cobralisk]

But windows isn't case sensitive!

Re:Microsoft just announced plans for their fix

[Anonymous Coward]

But I was going to suggest an abacus...

but then people would find out exactly how slow Office 2007 really is!

In OOXML?

[gvc]

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

Re:In OOXML?

[mennucc1]

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).

Re:In OOXML?

[Baricom]

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

Re:In OOXML?

[Anonymous Coward]

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!

Pentiums

[MyLongNickName]

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

Re:Pentiums

[644bd346996]

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

Re:Pentiums

[Fuji Kitakyusho]

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

Who are you going to call?

[renegadesx]

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.

Re:Who are you going to call?

[dvonhand]

Who are you going to call?

Ghostbusters?

Re:Who are you going to call?

[AJWM]

1 2 3 4 5 5 6 7 8 9

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

Re:Who are you going to call?

[rubycodez]

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!

Re:Who are you going to call?

[halcyon1234]

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}

Re:Who are you going to call?

[OverflowingBitBucket]

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. ;)

Re:Is anyone using Excel 2007?

[WK2]

Is anyone using Excel 2007?

65535 is a popular number. It is 2^16-1. This bug was discovered as soon as QA started (the day after release.)

It only gets worse.

[The Earl of Sandwich]

Try =6*9.

Re:It only gets worse.

[$RANDOMLUSER]

Try =6*9.

6 * 9 = 42
What's your point?

Re:It only gets worse.

[MostAwesomeDude]

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

Re:It only gets worse.

[RobNich]

Perhaps it's because 6 * 9 = 54.

Vista Sales

[xs650]

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

Re:Oh no!

[renegadesx]

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

News at 11

I can see the OOXML tag now...

[mad.frog]

        =850*77.1
</MultiplyLikeExcel2007>

Re:I can see the OOXML tag now...

[Anonymous Coward]

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

Lets wait and see :-)

Re:I can see the OOXML tag now...

[fractoid]

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

Re:I can see the OOXML tag now...

[l0b0]

That ... *Head explodes*

Unnecessary abstraction

[mikvo]

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).

Re:Unnecessary abstraction

[Rick Genter]

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

Re:Is anyone using Excel 2007?

[Anonymous Coward]

65535 is a popular number. It is 2^16-1 No wonder I'm not a popular number. I'm 2^10+313, and I always figured it was the ear wax or poor hygiene.

Retro

[starfishsystems]

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

Re:Dunno...

[Ford Prefect]

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?)

Re:Oh no!

[Anonymous Coward]

That was 6 minutes after your post, my time. It's been 20 minutes already! Where's my news!?

Re:Is anyone using Excel 2007?

[QuantumG]

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

Re:obviously malicious

[Gygash]

Corollary: Any incompetence distinguishable from malice is not sufficiently advanced.

Only Minnesotan Engineers use Excel

[Anonymous Coward]

Civil Engineers only use Excel in Minnesota.

This is why OOo Calc can never replace Excel

[swillden]

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.

Pay Day!

[johkir]

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

Re:But the important question is..

[Tablizer]

Does the built-in flight simulator still work?

As long as you stay below 65535 feet.

Re:Is anyone using Excel 2007?

[WK2]

65535 is a popular number. It is 2^16-1

No wonder I'm not a popular number. I'm 2^10+313, and I always figured it was the ear wax or poor hygiene.

1337 is a popular number too. Your problem is probably what you thought it was.

Although, around here, everybody talks about you. It's always Anonymous Coward this and Anonymous Coward that. Usually nothing good, but everybody here knows who you are.

Re:So?

[eggfoolr]

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.

Re:Microsoft Excel is the Worst Part of Office 200

[j01123]

I can blue screen my machines with Excel on a regular basis That's what you get for entering expressions that evaluate to 65,536.

New tag - OOPSXML

[Anonymous Coward]

I think we should all tag this story OOPSXML. :^)

The renewal form, hmmm?

[NotQuiteReal]

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

Re:The renewal form, hmmm?

[moosesocks]

If he's already paying $65,000 a month on rent, I think he just needs to find a new place altogether.

Change of base

[aaron alderman]

Maybe they convert to base 9.18956?

Re:Is anyone using Excel 2007?

[Anonymous Coward]

I got Vista and Office Ultimate for $15 each.

Dude, you got ripped off!

I just got a punch in the throat and a couple of knees to the sack for free.

Step 2 Found!

[OverflowingBitBucket]

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

Re:So What?

[GrahamCox]

literally don't know ANYONE who does any math, whatsoever, in Excel. It's all tables and primitive databases. The guy in the next cube does some pretty graphs. That's as close as it gets.

That's it then, definitive proof. Microsoft can breathe easy tonight, because you don't know anyone who would be affected by this bug. Ego problem, at all?

MS Licensing

[EricX2]

I bet they put that feature in for selling Vista volume licenses. In bundles of 850 the price is $77.10 each which is $100,000.

You must be new here.

[hedwards]

If it was funny then why wasn't it modded flamebait, with the GP being modded as insightful, you being modded funny, and myself being modded as being larger than a breadbox?

Re:Wow...

[Kreigaffe]

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

I've got a theory...

[XNormal]

It must be bunnies!

Re:I have another theory entirely.

[gogodidi]

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!

Re:I have another theory entirely.

[Anonymous Coward]

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

Re:Oblig.

[Stealth Potato]

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. ;_;

Re: Your sig

[Dolda2000]

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!

Re:Is anyone using Excel 2007?

[Sam_Brightman]

"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.

Re:Oh no!

[Slightly Askew]

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.

Re:Pido libro de reclamaciones por daños.

[jandrese]

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

Re:mod parent up!

[Anonymous Coward]

Not a conspiracy! Ha! Who do you think came up with IEEE 754?! Hint: It certainly wasn't Linus Torvalds or Steve Jobs!