Learners suffered learning loss in mathematics due to education disruptions caused by the COVID-19 pandemic. To address these challenges, the researcher conducted a study aimed to determine the effectiveness of Project MATH-YAGA (Yielding Authentic Results through Games and Activities) in improving the numeracy level of Grade 5 learners of Lual Elementary School. The study utilized the pre-experimental one-group pre-test-post-test design using universal sampling. Respondents of the study were 37 grade five learners. A 40-item validated researcher-made test instrument was utilized as a tool for data gathering. The mean and t-test dependent sample were utilized for data analysis using MS Excel Data Analysis Toolpak. The results of the study revealed that there were 21 or 56.76% non-numerates and 16 or 43.24% emergent learners during the pre-test with a mean of 10.24 and standard deviation of 3.15. After the implementation of Project MATH-YAGA for 10 months, the post-test was administered. It has a mean of 23.59 and a standard deviation of 7.14. The results denote that the average performance of the class increased. Only 1 or 2.70% were non-numerate, 9 or 24.32% were Emergent, 21 or 56.76% were Average Numerates, and 6 or 16.22% were Above Average. There is a significant difference in the numeracy level before and after the implementation of Project MATH-YAGA, which signifies an increase of 13.35 in the average score from the pre-test to post-test. The results proved the effectiveness of games and activities in improving the numeracy level of learners.