In this cross-national study, we explore the different ways of reasoning-and-proving (RP) presented in three 8th grade textbooks, one from each country: Turkey, Norway, and Slovakia. While the analysis revealed that all three textbooks contain similar numbers of problems involving some form of RP, differences exist in terms of the dominating ways of reasoning. In particular, while empirical reasoning dominates in the Turkish textbook, deductive reasoning is the dominant way of reasoning in the Slovak and Norwegian textbooks, with the Norwegian textbook having a significantly larger proportion of one-step deductions than its Slovak counterpart. This study is limited to only three countries, with only one textbook selected in each country. We discuss the findings and implications of our findings for textbook developers and teachers. Recommendations for further research, considering the limitations of the study, are also given.