Kastanien

Interesting things fall out of the sky in Freiburg. When we first arrived, it was Lindenbaum seeds, twirling down like little dancing fairies.

Two months later, horse chestnuts are tumbling out of trees in vast quantities, and pint-sized Kastanien hunters are out in full force. On Friday, Elias's teacher told her 24 students to start collecting nuts: they would use them to count to and appreciate the number 1000. By Monday, Elias had found 19 on a casual walk to the park. A more dedicated classmate had found 700. Together, the class collected over 3000.

Horse chestnuts are bitter and slightly toxic. When they fall, they burst out of their spiky husks with an explosive pop. Pretty, shiny, and smooth, they beg to be picked up, like pebbles on a beach. Crowded together in a bucket or makeshift basket (folding up the hem of your T-shirt works just fine), they slide and knock against one another with a pleasing clunk. They're useful for arranging and rearranging according to size and shape, for counting and recounting, for evaluating according to ever-changing point-assignment systems, for rolling, tossing, and juggling, and for poking toothpicks into to build toy animals.