The Effects of Using Length Models to Teach Fraction and Decimal Translation.

This article examines the effects of an intervention using explicit instruction and length models (such as number lines) to teach the relationship between fractions and decimals to U.S. fourth-grade students with mathematics difficulties (MD). Employing a multiple probe design with six students, the study found a functional relation between the intervention and improved performance in base-10 fraction magnitude understanding and fraction-to-decimal translation, with large effect sizes reported. The intervention, adapted from the Elementary Students in Texas: Algebra Ready (ESTAR) program, emphasized teaching fraction magnitude before decimal translation using visual length models to support a unified number system concept. Results suggest that length models can be effective instructional tools for students with MD, though the study notes limitations including the use of researcher-developed measures and calls for further research comparing length and area models and addressing complex rational number concepts.