In this work, we make a detailed study of compound proportionality problems from twelve 8th grade (age 13-14) Spanish textbooks. In particular, we perform an a priori, textual content analysis, classifying the problems according to their context, their structure and their position and role in the lesson where they appear. We also focus on the typology of the magnitudes used by the authors. Among other results, we conclude that, even if the number of problems varies slightly between different books, the treatment given to them is quite homogeneous regarding the context, structure and use of magnitudes: most of them are realistic missing value problems in which five quantities of extensive magnitudes appear. We also detect very few problems involving quantitative comparison or situations of 'inverse - inverse' type together with a very little use of intensive magnitudes.
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