Our parents out there are probably familiar with the concept of "new math," which was first introduced in the 1950s, 1960s, and 1970s. It was introduced after the Sputnik Crisis, which prompted the United States to prepare its students for STEM fields: science, technology, engineering and math. The goal was to teach students multiple different ways of learning different concepts rather than a single, uniform way of presenting material. Different student require different explanations! The New Math movement also put a new emphasis on students sitting and working in groups and using manipulatives (just like Mathnasium uses!).
(Sources for this blog post can be found here.)
Perhaps my favorite description of New Math comes from satirical lyricist Tom Lehrer in his song "New Math". Enjoy!