Digital technologies are essential for almost all human activities, so children should learn to work with them at schools. Some studies of the effect of using computers, tablets or cell phones at schools have been carried out, but in Czechia, where the research was conducted, the number of such studies is very low. We wanted to examine how tablets help pupils of the high school with learning social geography in Czech educational system. We worked with two classes of a high school in Prague. Two lessons were taught in each class, one with the Nearpod application on the tablet, the other without it. Pupils wrote pre-tests before the lesson and post-tests after it. Interviews were conducted with some of the pupils after the lesson with the tablet. Then, we worked with the results of both classes together and with the results of each class separately. We found out that pupils enjoyed the lessons with tablet, they felt more motivated and they thought, that they had learnt more with the tablet than without it. However, statistics showed us different results: the results of post-test were better when pupils had used tablet, but this finding was not valid for one of the two classes, where the difference between tablet and non-tablet lesson was not statistically significant. There were differences in pupils' relationship to digital technologies and in level of collaboration between the classes. The level of collaboration provides a good explanation of different success of both classes.