Bluebulb Projects' The Measure of Things presents:
680 is about nine-tenths the number of Kernels on an Ear of Corn.
In other words, the count of Kernels on an Ear of Corn is 1 times that amount.
(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.