Bluebulb Projects' The Measure of Things presents:
820 is about the number of Kernels on an Ear of Corn.
(Corn, a.k.a. Maize; Kernel a.k.a. Seed) (average) (for Dent Corn, a.k.a. field corn)
An average ear of dent corn, the kind grown to feed to animals and to make other foods, has an average of 800 kernels. Each acre of corn yields about 15,900 ears of corn.