Number theorists are always looking for hidden structure. And when confronted by a numerical pattern that seems unavoidable, they test its mettle, trying hard—and often failing—to devise situations in ...

Fractions knowledge by grade 5 uniquely predicts success in higher mathematics. Yet, assessments show that too many students struggle with this critical foundational math skill from grade 3 onward.

The average eighth grader is now three years below grade level in math. How can they do algebra if they’re struggling to divide fractions? Credit: Jill Brady/Portland Portland Press Herald via Getty ...