Assertion: glass marble | /r/HasProperty | about 8-10 mm
Facets:
Source sentences:
text: Supplies: a glass marble (standard size, about 8-10 mm in diameter); strips of wood, metal, plastic, cardboard, and similar materials 61 cm (24 inches) long, with various widths and textures to use as ramps; paper, aluminum foil, cloth, paint, cardboard, and similar materials for modifying the ramp surface; a meter stick or metric tape measure to measure the distance the marble rolls.