Team Sorting

Mel and Buttercup are trying a new adventure - team sorting.  The way it works is there are 10 calves in the pen.  A number between 0 and 9 is called.  One team member gets the calf with that number called while the other member guards the gate so the other calves do not get through.  For example, if number 6 is called, then the calf with the number 6 is first, driven to the adjoining pen, followed then by the consecutive numbers and beginning with 0 after the number 9 calf.
Buttercup had been used to just one cow or calf in the pen.  After she was worked with a little, she figured it out and did great!