The Development of Computational Thinking skills in elementary school students can be done through different activities, with or without the use of computers or technological devices. In this sense, the use of programmable robots brings many of the advantages of educational robotics for teaching fundamental aspects of computing. This paper describes an educational intervention that evaluates the use of four educational robot models to improve Computational Thinking with primary school students in the Huancavelica region in Peru, South America. This Peruvian region is known for its low human development rates, where the population still faces some important barriers regarding access to education and technology. The study was conducted with 6 to 13 years-old children for four weeks. Computational Thinking was evaluated using computational concepts like sequences, cycles, events, parallelism, conditionals, operators, and data manipulation. The evaluation results showed that children preferred robots that have more interaction, connectivity, and programming features, and they could contribute significantly to the development of Computational Thinking skills.