Apple has multiple times in the past called iOS as the world’s most advanced operating system. The company which was once known for its attention to detail and high level of quality now seems to be struggling to maintain the same standard. A bug in the iOS 11 calculator app prevents an iPhone/iPad from doing a calculation as simple as 1+2+3.

While the answer to the above calculation should be 6, chances are you are going to end up getting 23 or 24 as the result. The issue occurs when one tries to quickly add 1, 2, and 3 at which point the second tap on the ‘+’ symbol is not registered by iOS for some reason. While this might seem like a bug in the calculator app, it does not occur if one takes their time between taps. Since this is an iOS 11 issue, it is present on all iPhones and iPads running the OS.

To reiterate what I said above, the issue only occurs when you try to quickly enter 1+2+3. If you take your time between taps, the bug is unlikely to crop up.

Many users on Reddit put the blame on the long animation time which is not automatically cancelled when there is a user input like it should ideally happen. Now that this bug has been discovered, Apple will likely end up fixing it with the iOS 11.1 update which should drop later this month.

Now, it is unlikely that many people use the iOS 11 calculator app on a daily basis. As it is, many people prefer using other advanced calculator apps available on the App Store since the stock app is pretty barebones. Nonetheless, that should not be an excuse for Apple to let such a simple bug slip by in its testing.