In the late 1800s puzzles were published in newspapers; although the immediate object was to boost circulation, many of the puzzles stimulated serious mathematical thought.  Following the scientific revolutions of the early 1900s, books with titles like “What Is Mathematics?” written for the curious public became popular.  In the mid-to-late 1900s the Hands-On Science Center was born: mathematics was not extensively represented, but some places created exhibits that have  stood the test of time.  A few entrepreneurs started informal math education programs that continue to operate.

 

Since the year 2000 there has been an explosion in the number and variety of Math Outreach efforts.  Museums dedicated to mathematics, and math-themed performing arts (e.g. mime, street performance, stand-up comedy, musical theater etc.) have proliferated.  YouTube channels abound featuring skilled expositors of elementary and advanced math.  More mathematics is in the public sphere than ever before, but there is still a need for more extensive and sustained engagement.