A pearl is a beautiful, smooth ball from a weird place: the slimy inside of an oyster. If a scratchy grain of sand gets inside the oyster, the oyster smooths it by coating it with layers of “nacre,” or mother of pearl. The sand becomes a shiny little ball, and people make jewelry out of them. The world’s longest pearl necklace has 316,474 pearls and weighs almost 375 pounds. Very hard to wear!
Lace up: What shape is a pearl? (The yellow arrow is pointing to a pearl in the picture!)
Jog: If you hold 1 pearl on each tip of your fingers and thumbs, how many pearls do you have?
Sprint: If you have 12 pearls and need 3 more to string them around your wrist, how many pearls will you need in total?
Hurdle: If you added one more pearl to this 316,474-pearl necklace, how many would it have? See if you can say and write the number!
High Jump: If each pearl is about 1/2 inch wide, how long would a 30-pearl stretch be?
Answers:
Lace up: A circle (its cross-section, looking from the side), or in 3D it’s a “sphere.”
Jog: 10 pearls.
Sprint: 15 pearls.
Hurdle: 316,475 pearls.
High Jump: 15 inches.
