Understanding mathematics is an essential part of everyday life and can range from simple tasks such as using basic math skills to more complex tasks. Success in mathematics is a requirement for success in today's modern world. A gap in developing mathematical skills can create complications and interfere with job opportunities. Another basic essential for success in society is reading. There are important problems associated with students who cannot read successfully, such as higher dropout rates. Studies have shown that learning a foreign language during elementary school increases a child's ability to develop cognitive skills, and research has shown that proper development of cognitive skills improves a student's ability to read and perform mathematical skills successfully. Research studies involving dual-language/two-way immersion schools suggest that students at these schools obtain higher scores on achievement tests in both mathematics and reading. This study is a meta-analysis of studies involving dual-language/two-way immersion schools in an effort to confirm the hypotheses that (1) there are differences in student performance when comparing students who learn foreign language in elementary school versus those who don't, and (2) students score higher in reading, vocabulary, and/or mathematics if they learn foreign language in elementary school when compared to those who don't. The meta-analysis began with 51 quantitative research studies but was narrowed down to 17 after categorizing the studies. Using weighted effect sizes and Cohen's d, the results for the d values were 0.64 (medium) for vocabulary, 0.22 (small) for reading, and 0.11 for mathematics. Only homogeneity tests were calculated in each category. The Q values indicated homogeneity for the category of mathematics only. Therefore, additional research is suggested, beginning with heterogeneity testing. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]