You use a cow-culator. Or you round them up. Or any other method the commenters want.
A. because he wanted to help untie the human race.
A-CAW!
Camembert
A salt rifle.
A milk dud!
A cow with a cold.
He started counting then fell asleep.
With a cowculator.
Chase it round the garden
384 sir" "okay round them up" "400 sir"
A cow-culator.
Hitboxing!
Depends on which method you try....