Tessellations aren’t just eye-catching patterns—they can be used to crack complex mathematical problems. By repeatedly ...

Understand the replacement chain method, a crucial capital budgeting tool for comparing projects with different life spans. Explore how it works, its requirements, and alternatives.

National security, unlocked. Each Thursday, host Mary Louise Kelly and a team of NPR correspondents discuss the biggest national security news of the week. With decades of reporting from battlefields ...