iOS 11 Bug: Typing 1+2+3 Quickly in the Calculator App Won't Get You 6

calculatorappA bug in the built-in Calculator app in iOS 11 is getting some major attention this week, despite the fact that it's been around since iOS 11 was in beta testing.

At issue is a calculator animation that causes some symbols to be ignored when calculations are entered in rapid succession. You can try it for yourself: Type 1+2+3 and then the equals sign into the Calculator app quickly.

Due to animation lag introduced when adding two or more numbers together, your result is more likely to be 24 than 6.

The same goes for many other calculations -- the Calculator ignores some inputs unless you're entering numbers slowly enough to account for the light-up button animations that highlight the keys that are being pressed. Symbols do not register when tapped while a number button is still highlighted, resulting in incorrect calculations if you're inputting numbers quickly. Reddit user cplr describes the problem:

Any iOS developers will see what is wrong here: the bug is that the animation that lights up the button is blocking touch events until the animation completes. This is the default behavior for animations, but to make an app feel responsive it's best to find a way around that (it can be a one line fix, but sometimes it is complicated).

There are hundreds of complaints about the problem on reddit this week, but it's an issue that's been discussed on the MacRumors forums since the iOS 11 beta testing period. Throughout the beta testing process, the animation lag was not addressed, nor has it been fixed in any of the iOS 11 updates released so far. It's also still present in iOS 11.1.

Some users have experienced similar issues when using older versions of iOS, but the animation lag is noticeable enough in iOS 11 to make the Calculator nearly unusable when attempting to make rapid calculations.

Apple seem to be aware of the issue, because as The Loop points out, Apple employee Chris Espinoza says more than 70 people have filed a Radar report on the bug, alerting Apple to the problem. With it receiving so much attention, we could potentially see a Calculator fix in the next iOS 11 update.


In the meantime, iOS users who need a reliable alternative can use third-party apps like Calcbot and PCalc.

Related Forum: iOS 11

Popular Stories

iCloud General Feature Redux

iPhone Users Who Pay for iCloud Storage Receive a New Perk

Thursday March 20, 2025 12:01 am PDT by
If you pay for iCloud storage on your iPhone, Apple has a new perk for you, at no additional cost. The new perk is the ability to create invitations in the Apple Invites app for the iPhone, which launched in the App Store last month. In the Apple Invites app, iCloud+ subscribers can create invitations for any occasion, such as birthday parties, graduations, baby showers, and more. Anyone ...
Generic iOS 19 Feature Mock

iOS 19 Coming in June With These New Features

Thursday March 20, 2025 2:04 pm PDT by
While the first iOS 19 beta is still more than two months away, there are already plenty of rumors about the upcoming software update. Below, we recap the key iOS 19 rumors so far. visionOS-Like Design In January, the YouTube channel Front Page Tech revealed a redesigned Camera app that is allegedly planned for iOS 19. According to Front Page Tech host Jon Prosser, the Camera app...
iPhone 17 Pro Render Front Page Tech

iPhone 17 Pro Launching Later This Year With These 10 New Features

Sunday March 23, 2025 10:00 am PDT by
While the iPhone 17 Pro and iPhone 17 Pro Max are not expected to launch until September, there are already plenty of rumors about the devices. iPhone 17 Pro's alleged design via Front Page Tech Below, we recap key changes rumored for the iPhone 17 Pro models as of March 2025: Aluminum frame: iPhone 17 Pro models are rumored to have an aluminum frame, whereas the iPhone 15 Pro and iPhone...
iOS 18

Top 5 New Features Coming in iOS 18.4

Friday March 21, 2025 3:26 pm PDT by
We're not getting new Siri Apple Intelligence features in iOS 18.4 as expected, but the upcoming update does have quite a few new additions that will be worth upgrading for. We've rounded up the five best features to look forward to, and if you're not running the beta, you can expect to get access to these in early April. Priority Notifications If you have an iPhone or iPad that supports...
Windows Vista

Apple Might Be Having Its Windows Vista Moment, Says Analyst

Thursday March 20, 2025 6:52 am PDT by
Is Apple experiencing a "Vista-like drift into systemically poor execution?" That was a question posed by well-known technology analyst Benedict Evans, in a recent blog post covering Apple's innovation and execution, or seemingly lack thereof as of late. He is referring to Microsoft's Windows Vista operating system, which was widely criticized when it launched in 2007 due to software bugs,...
apple wallet drivers license feature iPhone 15 pro teal 1

Apple Says iPhone Driver's Licenses Coming to These 8 U.S. States, But Rollout Remains Slow

Wednesday March 19, 2025 6:55 am PDT by
In select U.S. states, residents can add their driver's license or state ID to the Wallet app on the iPhone and Apple Watch, providing a convenient and contactless way to display proof of identity or age at select airports and businesses, and in select apps. Unfortunately, this feature continues to roll out very slowly. It has been three and a half years since Apple first announced the...
iPhone 17 Pro Render Front Page Tech

Latest iPhone 17 Pro Dummies Highlight Apple's New Part-Glass Design

Thursday March 20, 2025 5:27 am PDT by
Seasoned leaker Sonny Dickson has shared more dummy models of Apple's upcoming iPhone 17 series, with the latest lot revealing a noticeable shift in Apple's iPhone Pro model design that goes beyond the much-talked-about new rear camera bar. Dickson points out that the iPhone 17 Pro dummy models feature an outlined area on the back, beginning just below the camera module and extending to the...
airpods pro 2 gradient

AirPods Pro 3 Launch Now Just Months Away: Here's What We Know

Tuesday March 18, 2025 9:13 am PDT by
Despite being released over two years ago, Apple's AirPods Pro 2 continue to dominate the wireless earbud market. However, with the AirPods Pro 3 expected to launch in 2025, anyone thinking of buying Apple's premium earbuds may be wondering if the next generation is worth holding out for. Apart from their audio and noise-canceling performance, which are generally regarded as excellent for...
CarPlay GM EV

GM Reportedly Blocks Dealership From Installing CarPlay in Newer EVs

Friday March 21, 2025 8:22 am PDT by
A few years ago, the American automaker General Motors (GM) announced that it would be phasing out support for CarPlay and Android Auto in its new electric vehicles, in favor of its own software platform. It was a controversial decision, as many drivers who are in the market for a new vehicle consider CarPlay to be a must-have feature. Looking to capitalize on the situation, one GM...

Top Rated Comments

desmond2046 Avatar
97 months ago
A calculator app is supposed to be a high school level project. Yet apple cannot get it right. This is extremely embarrassing.
Score: 97 Votes (Like | Disagree)
eyeseeyou Avatar
97 months ago
This is the calculator that provided the data that said the notch was a good idea.
Score: 55 Votes (Like | Disagree)
senzung Avatar
97 months ago
1+2+3 = 23, Courage!
Score: 46 Votes (Like | Disagree)
840quadra Avatar
97 months ago
Odd, animation for the + button slows down the actual input of addition. You have to wait for + animation to complete for it to take the rushed 2nd addition.

You would figure That turning on “reduce motion” would help a little, but no.

Maybe I can have my boss calculate my raise before this is fixed!!
Score: 40 Votes (Like | Disagree)
eoblaed Avatar
97 months ago
The calculator must be using that New Math we keep hearing about.
Score: 30 Votes (Like | Disagree)
Oblivious.Robot Avatar
97 months ago
Wait.. does that mean 1+2+3 is not 24?
WHAT! :eek:
Score: 28 Votes (Like | Disagree)