Do some quick additi in the iPhone calculator app? Or are you in the middle of a complex series of calculatis better suited to a spreadsheet, but did you use the calculator anyway? A wrg key can spell anything from boredom to disaster, requiring you to repeatedly hit the C key to reset the entire calculati and start again.
But this is not necessarily the case. With this quick professial advice, you can easily delete a single number at a time.
Welcome to 1977
The calculator applicati is a bit of a joke. It models the electric pocket calculators of yesteryear with absurd precisi, ignoring all the modern cveniences made possible during the decades of computer evoluti. There is no way to cancel an error, even without speaking of a fake roll of paper to allow you to browse the history of your additis and subtractis.