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

iPhone 17 Pro Lower Logo Feature 1

iPhone 17 Pro Coming Soon With These 14 New Features

Monday June 30, 2025 1:08 pm PDT by
Apple's next-generation iPhone 17 Pro and iPhone 17 Pro Max are less than three months away, and there are plenty of rumors about the devices. Apple is expected to launch the iPhone 17, iPhone 17 Air, iPhone 17 Pro, and iPhone 17 Pro Max in September this year. Below, we recap key changes rumored for the iPhone 17 Pro models:Aluminum frame: iPhone 17 Pro models are rumored to have an...
Apple Watch Ultra Night Mode Screen

Apple Watch Ultra 3 Launching Later This Year With Two Key Upgrades

Wednesday July 2, 2025 1:13 pm PDT by
The long wait for an Apple Watch Ultra 3 appears to be nearly over, and it is rumored to feature both satellite connectivity and 5G support. Apple Watch Ultra's existing Night Mode In his latest Power On newsletter, Bloomberg's Mark Gurman said that the Apple Watch Ultra 3 is on track to launch this year with "significant" new features, including satellite connectivity, which would let you...
iPhone 17 Pro Lower Logo Magsafe

iPhone 17 Pro's New MagSafe Design Revealed in Leaked Photo

Wednesday July 2, 2025 8:37 am PDT by
The upcoming iPhone 17 Pro and iPhone 17 Pro Max are rumored to have a slightly different MagSafe magnet layout compared to existing iPhone models, and a leaked photo has offered a closer look at the supposed new design. The leaker Majin Bu today shared a photo of alleged MagSafe magnet arrays for third-party iPhone 17 Pro cases. On existing iPhone models with MagSafe, the magnets form a...
Wi Fi WiFi General Feature

iOS 26 Adds a Useful New Wi-Fi Feature to Your iPhone

Wednesday July 2, 2025 6:36 am PDT by
iOS 26 and iPadOS 26 add a smaller yet useful Wi-Fi feature to iPhones and iPads. As spotted by Creative Strategies analyst Max Weinbach, sign-in details for captive Wi-Fi networks are now synced across iPhones and iPads running iOS 26 and iPadOS 26. For example, while Weinbach was staying at a Hilton hotel, his iPhone prompted him to fill in Wi-Fi details from his iPad that was already...
iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro Max Battery Capacity Leaked

Thursday July 3, 2025 5:40 am PDT by
The iPhone 17 Pro Max will feature the biggest ever battery in an iPhone, according to the Weibo leaker known as "Instant Digital." In a new post, the leaker listed the battery capacities of the iPhone 11 Pro Max through to the iPhone 16 Pro Max, and added that the iPhone 17 Pro Max will feature a battery capacity of 5,000mAh: iPhone 11 Pro Max: 3,969mAh iPhone 12 Pro Max: 3,687mAh...
iOS 18

Apple Releases Second iOS 18.6 Public Beta

Tuesday July 1, 2025 10:19 am PDT by
Apple today seeded the second betas of upcoming iOS 18.6 and iPadOS 18.6 updates to public beta testers, with the betas coming just a day after Apple provided the betas to developers. Apple has also released a second beta of macOS Sequoia 15.6. Testers who have signed up for beta updates through Apple's beta site can download iOS 18.6 and iPadOS 18.6 from the Settings app on a compatible...
maxresdefault

New MacBook With A18 Pro Chip Spotted in Apple Code

Monday June 30, 2025 8:05 am PDT by
Apple is developing a MacBook with the A18 Pro chip, according to findings in backend code uncovered by MacRumors. Subscribe to the MacRumors YouTube channel for more videos. Earlier today, Apple analyst Ming-Chi Kuo reported that Apple is planning to launch a low-cost MacBook powered by an iPhone chip. The machine is expected to feature a 13-inch display, the A18 Pro chip, and color options...

Top Rated Comments

desmond2046 Avatar
100 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
100 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
100 months ago
1+2+3 = 23, Courage!
Score: 46 Votes (Like | Disagree)
840quadra Avatar
100 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
100 months ago
The calculator must be using that New Math we keep hearing about.
Score: 30 Votes (Like | Disagree)
Oblivious.Robot Avatar
100 months ago
Wait.. does that mean 1+2+3 is not 24?
WHAT! :eek:
Score: 28 Votes (Like | Disagree)