What's 77.1 x 850? Don't ask Excel 2007

[Nick VR4]

A Microsoft manager has confirmed the existence of a serious bug that could give programmers and number crunchers a failing grade when relying on the latest version of Excel to do basic arithmetic.
The flaw presents itself when multiplying two numbers whose product equals 65,535. Fire up your favorite calculator and multiply 850 by 77.1. Through the magic of zeros and ones, you'll quickly get an answer of 65,535. Those using the Excel 2007, however, will be told the total is 100,000. The program similarly fails when multiplying 11 other sets of numbers, including 5.1*12850, 10.2*6425 and 20.4*3212.5, according to this blog post (http://blogs.msdn.com/excel/archive/2007/09/25/calculation-issue-update.aspx) from Microsoft manager David Gainer.


http://www.theregister.com/2007/09/26/excel_2007_bug/

[bradc]

lol!

[Nick Mann]

Being either gullible or a disbeliever, I have just tried it. They are right!

But (850*77.1)-1 does equal 65534, not 99999!

What a stoopid quirk!

[Nutter_John]

reminds me of the early pentium bugs

[AderC]

Remember the calculator in Windows 3.1 that thought 2.01 minus 2 was zero?!

aDe

[g8legnum]

There was also a quirk in the very first Sinclair pocket calculator (that shows my age I know) where if you divided 0.0 by 0.0 it became a clock counting up from zero in seconds.......:speechles

[bradc]

haha, that is really wicked!

[BuzzPuppy]

That's one of those magic binary numbers. 2^16 (2 multiplied by itself 16 times) is 65,536. But the values are from 0-65,535 so this is where it comes from :)

You see these values come up all the time.

2^8 = 256
2^16=65,536
2^24=16.7 million
2^32=4.3 billion

For the inner techno-geek in us ;)