Developing children's problem-solving and computing programming competencies is essential in the current information society. Hence, children can understand how their actions affect problems and their outcomes. Like in other in-developing countries, children grew along with technology in Chile, although students receive programming classes in secondary school. Nowadays, with high-level block-based programming languages, developing programming competencies in children seems a reachable task for enhancing problem-solving competencies. Nonetheless, children do not develop programming and electronics competencies because these technology competencies usually appear at high-education levels. Moreover, primary school teachers usually can avoid developing those competencies because they seem outside the knowledge that students must develop. Nowadays, we can use Arduino to improve the development of problem-solving and computing programming competencies. Because of its functionality and open hardware and software nature, Arduino is a good option for kids. In addition, they can become familiar with fundamental electronic components and design. Thus, Arduino helps children boost their thinking ability in a new dimension. We apply Arduino to teach essential electronic circuits and computer programming components to successfully solve different computing and electronic problems, such as turning on and off a set of lights and reading sensors to react regarding the obtained values. Given the relevance of the problem-solving competence, the open nature of Arduino, and the applicability of Arduino to develop programming competence using block-based programming languages, this article aims the development of problem-solving and computer programming competencies in primary school children. A relevant associated result is that children who participated in the experiment improved their average score in school. These children are from a primary school in Valparaíso, Chile.