The study was conducted to determine the effect of cooperative learning strategies in the computational skills of first year high school students at Binugao National High School, Toril District, Davao City for School Year 2007-2008. It made use of the experimental method of research using non-equivalent control group. The experimental group was exposed to the cooperative learning strategies while the control group adopted traditional lecture-discussion method. The students score on the Otis-Lennon School Ability Test (OLSAT) served as the criteria for grouping. To evaluate the effect of cooperative learning strategies on the mathematics performance of the first year high school the pretest –posttest were analyzed using ttest for independent and dependent sample means. The result showed that cooperative learning strategies were found to be effective tools in improving the performance of the students. The findings of the study revealed that traditional lecture-discussion method of teaching was also effective; however, it was not as much as the experimental group. It was recommended that cooperative learning strategies be used in teaching by mathematics teachers to help students improve their computational skills.