For example, to perform two calculations at the same time and thus simplify some procedures; or to create two lists of complements. But in fact, once you use it, you'll find that the dual-calculator function can be used for a lot more calculations than you thought. And who knows, maybe the double calculator will become your primary calculator.

The design is clear, with large buttons for pleasant use. The two calculators are easy to distinguish from each other because they are different colors.
Both calculators have basic functions: addition, subtraction, multiplication, division, remainder, and negative numbers. Depending on the orientation of the device, the dual calculator adapts to portrait and landscape orientation.