The purpose of this paper is to develop mathematics learning contents for elementary school 3rd graders and to verify the educational effectiveness of contents developed. An ADDIE model was applied to develop mathematics learning contents based on storytelling for concept learning. After extracting 54 concepts from the mathematics curriculum, researchers designed strategies using concepts that were combined with context which is familiar to young students. Researchers implemented a survey and interview to students and teachers to verify the effectiveness of contents. As a result, the understanding, interest, concentration, and expectation of students toward the contents developed were very high, and teachers also mentioned that these contents could be very useful teaching materials for motivation.