The purpose of this mixed methods study was to investigate the implementation of a researcher-created numberless word problem instructional unit designed to introduce second-grade students to word problems in the semantic category of "compare with the word more, smaller unknown." The 10-day instructional unit incorporated three elements: the numberless word problem routine, purposeful questions in five categories, and a six-step framework that included the use of a bar model to visually represent the quantities in a problem. Data were collected from 27 second-grade students using a six-question pretest and posttest that included three word problems in the "compare with the word more, smaller unknown" category and three word problems in the "compare with the word more, bigger unknown" category. Mean scores increased from 2.96 (pretest) to 3.78 (posttest) and the number of correctly solved problems increased in both semantic categories. An error analysis determined that operational errors (e.g., using addition instead of subtraction) were the most frequent errors present but the frequency of those decreased on the posttest. Students showed an increase from the pretest to the posttest in their use of a bar model to solve word problems. A paired-samples t test revealed a statistical significance (t (26) = 3.11, p < 0.01, Cohen's d = 0.599). [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.]