The purpose of this study was to understand how children use meta-cognition in their everyday problem-solving, particularly making monetary decisions. A particular focus was to identify components of meta-cognition, such as regulation of cognition and knowledge of cognition observed in children's monetary decision-making process, the roles of meta-cognition in children's monetary decision-making process, and the emerging factors that help to explain children's monetary decision-making processes. Data were collected from 136 mixed ability fifth-grade students (typically 10 years of age) from six different government primary schools in Singapore through focus group and one-to-one interviews. Using grounded theory, it was found that children's monetary decision-making is a complex process, that children often reflect upon unwise decisions and unpleasant experiences, and that parental involvement was an influential factor in their children's decision-making. (Contains 3 figures.)