In Japan, study of probability is positioned after the secondary education stage. On the other hand, there have been discussions on probability as one of the important contents of primary education in other countries for a long time, and this has been reflected in the curriculum as well. Given this, this study focuses on the influence of the size of the value of a random variable on the comparative judgment of probability values to gain insights for teaching the notion of probability in elementary school through the analysis of the results of a cross-grade survey.