Numerical skills are essential to make informed decisions in our daily life. Unfortunately, many people lack basic numeracy, which limits their ability to accurately interpret risks (i.e., risk literacy). In this paper, we provide an overview of research investigating the role of numeracy in two prominent domains, where most research was concentrated, health and finance. We summarize what has been learned so far in these domains and suggest promising venues for future research. We conclude that it is important to conduct interventions to improve numeracy in less numerate individuals and to help them make informed decisions and achieve better life outcomes.