The AnimalWatch tutoring system provides students with instruction in algebra readiness problem solving, including basic computation, fractions, variables and expressions, basic statistics and simple geometry. Students solve word problems that include authentic environmental science content, and can access a range of multimedia resources that provide instructional scaffolding, such as video lessons and worked examples. Because providing learners with choices is associated with enhanced motivation, AnimalWatch is designed to allow students to decide what science topic they would like to learn about, and when they would like to navigate between different modules in the system. Several evaluation studies in classroom settings have found positive effects of AnimalWatch on study-specific measures of problem solving. Benefits have been strongest for students who are struggling in math, suggesting that technology-based learning can be especially effective for this population.