Mathematics literacy, which encompasses vital life skills such as learning to communicate and justify reasoning, is important for all people throughout their lives. Technology tools such as technology-based graphic organizers (TBGOs) provide universal accessibility supports for learners who experience difficulties with a variety of aspects of mathematics, from organizing their problem-solving process to expressing and defending their reasoning in writing. This study was designed to investigate the functional relation between a TBGO with embedded self-regulated learning (SRL) strategies on the quantity and quality of students' argumentative mathematical writing (MW) and changes in mathematics performance. The study aimed to improve MW and mathematics problem-solving as well as the self-efficacy for SRL in mathematics problem solving and writing of seventh-grade students with and without disabilities struggling with mathematics learning. A multiple-baseline across-participants study was conducted with 18 seventh-grade students, both with and without disabilities. Data were collected on students' MW performance (number of words and symbols [TWWS], transition words [TWs], and MW quality [MWQ]) as well as mathematics problem-solving (number of problems solved correctly) across four phases: (a) baseline (solving problems and writing on the computer without the TBGO), (b) Intervention with TBGO (solving problems and writing on the computer with the TBGO), (c) maintenance (solving problems and writing on the computer without the TBGO), and (d) generalization (solving different problems and writing on the computer with and without the TBGO). Visual and statistical analyses were used to evaluate changes in students' MW and problem-solving. Statistical and thematic analysis of students' self-efficacy for SRL ratings for MW and mathematics was also conducted. Results indicated moderate evidence of a functional relation between the MW intervention with TBGO and all MW measures. Additional analyses revealed significant differences in students' pre- and post-mathematics problem-solving and ratings of self-efficacy beliefs. Student interview data were used to discuss the social validity of this novel technology-based intervention. Most students reported that the TBGO was helpful for supporting their MW and problem-solving. Limitations as well as implications for future research and practice are also addressed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]