An amount or portion allocated according to the number of people present; per person (i.e., for each person).
会議用に人数分の資料を印刷しておいてください。
Please print copies of the materials for the number of people attending the meeting.
ケーキは人数分に切り分けてテーブルに置いた。
I cut the cake into portions for each person and put them on the table.
飲み物は人数分用意したので、足りなくなる心配はありません。
I prepared drinks for everyone, so there is no worry about running out.