The oyster may look like just another slimy sea creature with a shell. But some oysters hold a prize inside: a pearl. When a scratchy grain of sand gets inside, the oyster coats it with smooth stuff called “nacre.” The layers build for up to 6 months to make a shiny pearl. This bird, called an oystercatcher, probably doesn’t know all that. It just cracks open oysters to eat them – and apparently to make necklaces!
Wee ones: Who makes a pearl faster, an oyster that takes 4 months or one that takes 7 months?
Little kids: If the oystercatcher catches 8 oysters and 3 are holding pearls, how many aren’t? Bonus: If the oystercatcher needs 16 pearls in total, at least how many more oysters does he need to find?
Big kids: Oystercatchers lay 2-3 eggs in one “clutch” (batch of eggs). If an oystercatcher makes necklaces for all 3 of its kids with 10 pearls on each, how many pearls does it need? Bonus: If instead it finds 26 pearls, how many pearls at most can each necklace have if all 3 have to be the same? Will there be any pearls left over?
Answers:
Wee ones: The oyster that takes 4 months.
Little kids: 5 oysters. Bonus: 13 more, since he has only 3 to start.
Big kids: 30 pearls. Bonus: The necklaces can have 8 pearls apiece at most, since 9 apiece would need 27 pearls in total. There will be 2 unused pearls out of the 26.
