This study investigated the effectiveness of "Math Explorer" at enhancing the word problem-solving skills of students with mathematics difficulties (MD). The study, which had a multiple-probe-across-subjects design, was conducted over 18 weeks. Four students with MD in Grades 2 and 3 participated. All students were able to use the four-step cognitive and three-step metacognitive strategies to solve addition and subtraction word problems and improved their word problem-solving performance on the computer- and paper/pencil-based tests. After the intervention phase, three out of the four students successfully maintained their improved word problem-solving performance levels during the follow-up phase. Implications for teachers and future software programmers are discussed, and directions for future computer-assisted instruction (CAI) research are suggested. (Contains 2 tables and 2 figures.)