Probabilistic reasoning underpins much of middle school students' future work in data analysis and inferential statistics. Unfortunately for many middle school students, probabilistic reasoning is not intuitive. One specific area in which students seem to struggle is determining the probability of compound events (Moritz and Watson 2000). Research has suggested that using simulations to introduce this topic has the potential of advancing students' intuitive understanding of this concept (Biehler et al. 2013). In this article, two activities are shared that engage students in reasoning about compound probabilities. By using CODAP (Common Online Data Analysis Platform) to engage students in simulations and carefully scaffolding advancing questions, teachers can uncover students' intuitions about these ideas and advance their reasoning about compound probabilities by helping them make connections between experimental and theoretical probabilities.