They’re probably the most familiar interfaces on the planet: the numeric keypads on our mobile phones and calculators. Yet very few notice that the keypads’ design has remained unchanged for nearly half a century in the face of evolving global design norms and conventions.
Even fewer users notice another startling design feature: the phone’s keypad is the inverted version of the calculator’s. This article explores the roots of this disparity and proposes a better solution. We will discuss how to simplify and adapt a traditional numeric interface to a minimalist design norm by taking advantage of modern touch-driven modes of human–mobile interaction.