<p class="ecxecxmsonormal">The main objective of the present paper is to introduce a didactic play designed in order to help the students of early years of primary education the understanding of the concept of scale. The understanding of this concept prepare them to the correct interpretation, in further years, of this conventionalism in plans and maps. Empirical research we have conducted on the effectiveness of this material, testing in schools in the city of Madrid, has shown a high degree of usefulness for teaching and learning the subject. The use of this material in the classroom has been done from active teaching, giving a central role to the ludic methodology, and has allowed the achievement of meaningful learning by the students from their previous ideas and conceptual representations.</p>