This article describes a pilot study in which pre-service elementary teachers (PSTs) used rectangular area models on base-10 grid paper to begin making sense of multiplication of decimal fractions. Although connections were made to multi-digit whole number multiplication and to the distributive property, the PSTs were challenged by interpreting geometric aspects of the models they produced. In the context of these activities, the PSTs confronted concepts of dimensionality, unit labeling, and unit coordination that were not at issue in the domain of whole numbers. Tasks that help learners distinguish between one- and two-dimensional measurements are suggested as potential remedies. (Contains 6 figures.)