We report on a teacher development program aimed at improving mathematics teaching and learning from grades 5-9. The 18-month largely online program arose from a partnership of mathematics education researchers, mathematicians, physicists, and nine school districts. The program employed functions as a lens to reinterpret and interconnect content…

Students expose various intuitions in probability comparison and calculation tasks. Large volumes of research looked into these intuitions by categorizing learners' strategies, but fewer studies considered how these intuitions may be associated with learners' judgments. Even fewer examined the mixed effects of multiple intuitions held by the same…

This study examined a cohort of middle school pre-service mathematics teachers' understanding of the rate of change as they engaged in a model development sequence. By adopting a design-based research perspective, a model development sequence on the concept of rate of change has been designed and implemented as part of a mathematical modeling…

Mathematics growth trajectory plays a significant role to predict future outcomes and careers. We examined the existence of different growth trajectories in mathematics during the late elementary-school period (from Grades 4 to 6) and the relationship between the trajectory group classification and later mathematics achievement (Grade 8). Then,…

This study investigates preservice middle school mathematics teachers' understanding of statistics and probability and provides a cognitive diagnostic assessment of their strengths and weaknesses on these subjects. A statistical reasoning test that included 15 multiple-choice and 5 open-ended items was developed from the perspective of the…

Central in the frameworks that describe algebra from K-12 is the idea that algebraic thinking is not a single construct, but consists of several algebraic thinking strands. Validation studies exploring this idea are relatively scarce. This study used structural equation modeling techniques to analyze data of middle school students' performance on…

We focus on teachers' ways of leading whole class discussions (WCDs) in mathematics, with the goal of uncovering their traces (if any) in their students' responses (a) while participating in the WCDs and (b) in the written responses in a final test. For this purpose, two 8th-grade probability classes learning a 10-lesson unit with different…

Attending to the whole unit that a number refers to in a mathematical problem situation and showing flexibility in coordinating different units are foundational for mathematical understanding. In this study, we explored teachers' attention to and flexibility with referent units in situations involving fractions and fraction multiplication. Using…

The present study uses a short, computerized task to investigate individual differences among middle school students in terms of the intuitions and strategies that they use to compare fractions. To tap into their intuitions about fractions, students were presented with pairs of fractions on the screen for a limited time of 10 s. Fraction pairs to…

This study investigated preservice middle school mathematics teachers' (PSTs) understanding of proportional and nonproportional relationships and their abilities to differentiate these relationships from each other. The PSTs' abilities to interpret and represent proportional and nonproportional situations and solution strategies were also…