The overall aim of the proposed project is to test the efficacy of a relatively new, well-developed math program on the math achievement of elementary school students in mainstream classes in urban schools. Use of this program is increasing in Canada and the United Kingdom. Preliminary findings derived from uncontrolled trials and our own pilot, randomized controlled trial suggest it may yield meaningful gains in math achievement for both at-risk and achieving students, as indexed by their performance on national exams, in national math competitions, as well as on standardized measures of math achievement. However, the program has yet to be rigorously evaluated to determine its relative efficacy compared to the math programs typically used by school boards. The program provision of grade-specific teacher's guides and student workbooks (for grades 1 to 8), and minimal teacher training, points to its potential utility for full-scale implementation, should its efficacy be confirmed.

Inclusion Criteria:

• The students must: have sufficient command of English to understand their teacher's instructions (as judged by their teacher, ELL students will be included provided they meet this criterion). They must have a signed parental consent form and also assent to participate in the study.

Exclusion Criteria:

• The students must have no uncorrected sensory, neurological, or physical impairments that would preclude the use of manipulatives, perceiving written math materials and figures, or hearing the teacher's instructions.