I’ve been out of school for decades, and I don’t spend my days solving equations (I’m more of a word person). Still, I like to think I have a solid grip on basic math: I can usually gauge whether a ...

Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific ...

She’s right—using simultaneous equations does get really complicated, and if you’d like to send me your work for the solution, I’d love to see it. But the system is also kind of a trick. Like a sudoku ...