The low numeracy literacy ability of students in the number division material shows the need for learning media innovations that are able to provide concrete and meaningful learning experiences. This research aims to develop a learning media for Congklak Numbers (COLA) to improve the numeracy literacy of grade III students of SDN Klepek. The research uses the Research and Development (R&D) method with the ADDIE model which includes the stages of analysis, design, development, implementation, and evaluation. The research subjects consisted of one classroom teacher and 40 grade III students of SDN Klepek. The research instruments include interview guidelines, observation sheets, expert validation sheets, teacher and student response questionnaires, and numeracy ability tests. The data was analyzed descriptively, qualitatively and quantitatively using percentage analysis to measure validity and practicality, as well as a paired sample t-test to determine the effectiveness of the media. The results of the study showed that the Congklak Numbers (COLA) media obtained a validity level of 98% from material experts and 86% from media experts with a very valid category. The practicality of the media obtained a percentage of 96% of teachers and 97% of students in the limited trial, as well as 95% of teachers and 94% of students in the broad trial with the very practical category. The results of the effectiveness test showed an increase in the average score of students from 65 to 93 in the limited trial and from 63 to 91 in the large trial with a significance value of 0.001 (p<0.05). Thus, the Congklak Numbers (COLA) media is declared valid, practical, and effective so that it is suitable for use as a mathematics learning medium to improve students' numeracy literacy in elementary school grade III number division material