CRA
Concrete-Representational-Abstract
CRA is an explicit-instruction sequence for mathematics in which students first manipulate three-dimensional objects (concrete), then work with two-dimensional drawings or diagrams (representational), and finally operate on symbolic notation alone (abstract). The meta-analytic review of 30 single-case design studies by Ebner et al. (2025, Learning Disabilities Research & Practice 40(1)) yielded a statistically significant Tau-BC effect size of 0.9965, and CRA is listed as an evidence-based practice by the What Works Clearinghouse for students with math learning disabilities.
Regulatory Citation
Example in Practice
A student learning two-digit subtraction first uses base-ten blocks to physically regroup, then draws sticks-and-dots representations on paper, and finally performs the standard algorithm symbolically — with mastery required at each stage before advancement.
Key Research Citations
- ·Ebner, MacDonald, Grekov & Aspiranti (2025, Learning Disabilities Research & Practice 40(1)) — CRA meta-analysis, Tau-BC=0.9965
- ·Bouck, Satsangi & Park (2018, Remedial & Special Education 39(4):211-228) — CRA EBP synthesis
- ·Witzel, Riccomini & Schneider (2008, Intervention in School and Clinic 43(5):270-276) — Secondary CRA
Full bibliography available on the Research page.
This glossary entry is educational. It is not legal or clinical advice. Consult a qualified attorney or licensed clinician before making decisions that rely on this summary.