Feeds

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

65,535 = the Number of the Beast

Secure remote control for conventional and virtual desktops

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 from Microsoft manager David Gainer.

He stressed that the bug, which was introduced when Microsoft made changes to the Excel calculation logic, occurs only in the value Excel displays in a cell. The result stored in memory is correct. "Said another way, 850*77.1 will display an incorrect value, but if you then multiply the result by 2, you will get the correct answer," Gainer wrote.

Of the 9.214*10^18 different floating point numbers that Excel 2007 can store, six of them are susceptible to the flaw.

We're still at a loss as to why the latest and greatest version of Excel would get tripped up on equations totaling 65,535. The number, of course, is the highest that can be represented by an unsigned 16 bit binary number, so people who muck around with computers encounter it on a daily basis. For example, Internet protocol supports 65,535 TCP and UDP ports.

Microsoft engineers are in the final phase of testing a fix. It should be available for download soon, Gainer said. ®

Secure remote control for conventional and virtual desktops

More from The Register

next story
Be real, Apple: In-app goodie grab games AREN'T FREE – EU
Cupertino stands down after Euro legal threats
Download alert: Nearly ALL top 100 Android, iOS paid apps hacked
Attack of the Clones? Yeah, but much, much scarier – report
You stupid BRICK! PCs running Avast AV can't handle Windows fixes
Fix issued, fingers pointed, forums in flames
Microsoft: Your Linux Docker containers are now OURS to command
New tool lets admins wrangle Linux apps from Windows
Bada-Bing! Mozilla flips Firefox to YAHOO! for search
Microsoft system will be the default for browser in US until 2020
Facebook, working on Facebook at Work, works on Facebook. At Work
You don't want your cat or drunk pics at the office
Soz, web devs: Google snatches its Wallet off the table
Killing off web service in 3 months... but app-happy bonkers are fine
prev story

Whitepapers

Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
Getting started with customer-focused identity management
Learn why identity is a fundamental requirement to digital growth, and how without it there is no way to identify and engage customers in a meaningful way.
How to determine if cloud backup is right for your servers
Two key factors, technical feasibility and TCO economics, that backup and IT operations managers should consider when assessing cloud backup.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Internet Security Threat Report 2014
An overview and analysis of the year in global threat activity: identify, analyze, and provide commentary on emerging trends in the dynamic threat landscape.