Teaching Aids

Mr. Math vintage 1972 teaching aid tools: 16,200 ppm Lead (90 ppm and up is unsafe for kids)

Unifix Math Counting Blocks Teaching Aid from Portland Public Schools: 1330 ppm Cadmium [a known carcinogen.]

#AskTamara: Do Glass Dragon Tears Have Lead? (Aka: Squashed Marbles, Glass Drops or Mancala Stones?)