This quasi-experimental post-test only control group designed quantitative study examined whether or not members of an experimental group of participants who utilized two metacognitive strategy training regimens experienced a significant increase in their ACT mathematics sub-test scores compared to a group of students who did not utilize either of the study's metacognitive strategy training regimens. Using a post-test only control group design required 2 groups of participants: 1) the experimental group, and 2) the control group. Participants began the study's treatment on October 26, 2015, and the study ended on December 12, 2015, when all participants of the study took the regularly nationally scheduled ACT examination. The study's treatment was comprised of a series of worksheets of mathematical problems constructed similarly to those found in the ACT study guide published by ACT, Inc., and a set of 6 metacognitive relevant questions that were required to be answered after participants of the experimental group completed each worksheet. Both of these metacognitive strategies have previously been shown to help improve users' metacognitive processes and, by extension, their mathematics achievement. The control group did not receive the study's treatment. According to Campbell and Stanley (1963, p. 26), independent sample t test analysis is the preferred method of analyzing data generated in a post-test only control group design study. Accordingly, the ACT mathematics sub-test scores of the experimental and control groups were analyzed using independent sample t test analysis once the data were collected at the end of this study. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]