Why do virtual calculator UIs (especially desktop ones) have the numbers laid out when users typically use the keyboard instead

Question

Just curious, why do virtual calculators on desktops even have the numbers and symbols added to the UI.

Here's an example of what I mean

Windows Calculator

macOSCalculator

On desktops, the primary mode of input is the keyboard and I imagine in most cases, users would use the physical keyboard not only to input numbers but also for basic operations like addition, subtraction etc.

If that's the case, does the visual depiction of numbers and operations on the UI add any value. Is there an official research, statement explaining this better?

Answer 1

Not all users are the same or have the same possibilities for interaction

Years ago I was a teacher in a two-month QuarkXPress course. An extremely difficult layout and text editing application for those who are not used to working with it, with different keyboard shortcuts, submenus, and commands. I had always seen it as a redundant application, with repeated, hidden, and tremendously absurd options. Until I had to give this course to which I refer. Suddenly everything made sense. The course was in a rehabilitation center for paraplegics, most of them due to traffic accidents. They used a spinning ball as a mouse. In fact, they used all the options that seemed redundant to me in the application, which, accustomed to a couple of keyboard shortcuts, I had to relearn them with their real name, meaning, location and action. Since then every time I visualize redundancy in an interface, I analyze it with two or three different eyes.

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