The purpose of this research was to develop a skill-practicing lesson for Laplacetransform using Maple mathematical package, with process efficiency (E1) andachievement efficiency (E2) based on 80/80 efficiency criteria for the media. Thesample consisted of 20 undergraduate students enrolled in the differential equationcourse during the second semester of academic year 2008 at Industrial TechnologyCollege, King Mongkut’s University of Technology North Bangkok. The studyexperiment is based on one-group pretest-posttest design. The research tools consistof a skill practicing lesson for Laplace transform using a mathematical package,pretest and posttest examination papers, and attitude questionnaire. The resultsshowed that the efficiency of the skill practicing lesson is 83.75/81.17, which is higherthan the 80/80 efficiency criteria. There is a highly significant difference betweenpretest and posttest scores with p-value = 0.00; the preferred score of the skill lessonis above the average, and without any problems using Maple. Some conclusions andsuggestions from this research are: the CAS programs should be used in mathematicssubjects, especially calculus and analytical geometry; students may be able to applythe CAS program to complexity problems; students have time to do more practiceexercises and gain more experience in conceptual ideas more easily and simply.