In order to be well-educated citizens in the 21st century, children need to learn computing in school. However, implementing computing education in schools faces several practical problems, such as a lack of computing teachers and time in an already overloaded curriculum. A solution may be a multidisciplinary approach, integrating computing education within other subjects in the curriculum. The present study proposes an instructional unit for computing education in social studies classes, with students learning basic computing concepts, including computational thinking, by programming history related games using Scratch. The instructional unit is developed following an instructional design approach and is applied and evaluated through a pilot case study in four classes (5th and 7th grade) with a total of 105 students at a school in (omitted for submission). Results provide a first indication that the instructional unit enables the learning of basic computing concepts (specifically programming) in an efficient, effective and entertaining way increasing also the interest and motivation of students to learn computing.