This learning activity packet (LAP) outlines the study activities and performance tasks covered in a related curriculum guide on milling machines. The course of study in this LAP is intended to help students learn to set up and operate a horizontal mill. Tasks addressed in the LAP include mounting style "A" or "B" arbors and adjusting arbor support bushings, using machine controls properly, mounting a cutter to an arbor, mounting and aligning a swivel-base vise, aligning work mounted to a table, aligning angle plates at right angles to columns, mill squaring a workpiece mounted in a vise, performing face milling operations using a style "C" arbor, milling a keyway with a staggered-tooth mill cutter, performing a straddle milling operation, milling an angle with a single-angle mill cutter, and milling to blueprint specifications using machine controls. Included in the LAP are unit and specific objectives, a pretest, information and assignment sheets, cross-references to the curriculum guide, job sheets, and answers to the pretest and the assignment sheets. Page numbers in the LAP are coordinated with those in the curriculum guide. (MN)