Re “State’s ‘math wars’ are hurting Black, Latino students” (April 23): I was an algebra teacher into three decades and found one basic principle: If you don’t know basic arithmetic, i.e., how to add, ...

At Del Rio STEM Academy, a magnet school in Oceanside Unified School District, first-grade teacher Katherine Sebastian uses her hands as she talks through math problems. Her hands come together in a ...

In this playlist I show you how to understand set theory. I introduce sets as venn diagrams, mapping and as sets of numbers.