Windows Calculator

Windows Calculator hides a surprising amount of range behind a plain keypad. A navigation menu swaps the whole interface between standard, scientific, programmer, graphing, and a long list of unit and currency converters, so a single utility covers cases that usually need separate apps. Its strongest interface choice is the persistent history panel: every prior result stays listed and re-clickable, and a running expression line shows the full operation rather than just the latest number — a direct correction of the classic calculator's amnesia. Memory keys get their own visible tray too. The downside is that the mode menu buries that breadth; most users never learn the programmer or graphing modes exist, and converter selection through stacked dropdowns is clumsy compared with the crisp main keypad.