<![CDATA[The low achievement of students' mathematics learning outcomes and the suboptimal participation of students during the learning process are the basis for implementing this research. The purpose of this research is to analyze the effect of peer tutoring learning on the mathematics learning outcomes of fifth-grade students of SDN Tugu 1 Cimanggis Depok. The quantitative approach was implemented using a posttest-only control design. The research population included all fifth-grade students of SDN Tugu 1 Cimanggis Depok, while the sample used was 53 students divided into 27 students in the experimental class and 26 students in the control class. Data collection was based on mathematics learning outcome tests that had undergone validity and reliability testing. A series of data analysis included normality tests, homogeneity tests, and hypothesis testing using independent sample t-tests. The results of data processing showed that the distribution met the assumptions of normality and equal variance between groups. Hypothesis testing produced a significance value (Sig. 2-tailed) of 0.000 which was below the threshold of 0.05 so that H₀ was not accepted and H₁ was declared valid. The average learning outcome in the experimental class was recorded at 70.67, while the control class was 54.31 with a difference indicating an advantage in the experimental class. The calculation of the effect size (Cohen's d) of 1.048 leads to a large category. These findings indicate that peer tutoring learning has a significant and strong influence on the mathematics learning outcomes of fifth-grade students at SDN Tugu 1 Cimanggis Depok, so this method can be considered as an alternative learning strategy to improve mathematics learning outcomes in elementary schools.]]>
