The aim of this study was to investigate the effect of the Scratch and Lego Mindstorms Ev3 programming activities on academic achievement with respect to computer programming, and on the problem-solving and logical-mathematical thinking skills of students. This study was a semi-experimental, pretest-posttest study with two experimental groups and a control groups. A total of 75 students were divided among all three groups. Scratch-based game activities were applied to Study Group I. Lego Mindstorms Ev3-based design activities were applied to Study Group II. A C++ editor-based teaching activity was applied to the control group. The academic achievement test was developed within the scope of this study (Kr-20 = 0.71). The Logical-Mathematical Intelligence Sub-Scale was used (Cronbach alpha is 0,925). Problem-Solving Inventory was used (Cronbach alpha is 0,86). Data was evaluated using frequency, percentage, arithmetic mean, standard deviation, and Anova analyses. The educational program based on Scratch-related game activities made a more positive contribution to the logical-mathematical thinking skills of students than the educational programs based on Lego Mindstorms Ev3 design activities and traditional teaching activities, and this contribution was especially significant for the mathematical relationship factor.