WATSONVILLE — Jessica Serna Castaneda leads a group of campers building a 24-cell octahedron last week at Summer Math Circle Camp at Sequoia High School in Watsonville. Eighteen students, grades 5-9, ...

I had never heard the term, “math circle,” until a few weeks ago when I stumbled across an article in The Atlantic about the growing number of American kids excelling in the highest levels of math. It ...