Okul öncesi, ilkokul ve ortaokul dönemlerindeki çocukların somut yaşantılar ile daha hızlı ve kalıcı öğrenebileceği düşünüldüğünde, konuları somutlaştıran materyallerin öğretimde kullanılması oldukça önem taşımaktadır. Yapılan bu araştırmanın amacı, araştırmacı tarafından geliştirilen sayı şeridi materyalinin ilkokul 4. sınıf öğrencilerinin matematik başarıları ve tutumlarına etkisini incelemektir. Araştırmada nitel ve nicel araştırma yöntemlerinin bir arada kullanıldığı karma yöntem kullanılmıştır. Araştırmanın örneklemini 2016-2017 öğrenim yılında Diyarbakır ilinin Bağlar ilçesindeki bir ilkokulun 4. sınıflarında öğrenim gören 86 (43 deney ve 43 kontrol) öğrenci oluşturmaktadır. Araştırmanın verilerini toplamak için araştırmacı tarafından geliştirilen başarı testi ve tutum ölçeği kullanılmıştır. Başarı testi ve tutum ölçeği hem uygulama öncesi hem de uygulama sonrası kontrol ve deney gruplarına uygulanmıştır. Elde edilen veriler SPSS 24.0 paket programı kullanılarak analiz edilmiş ve başarı testinin güvenirlik katsayısı (Kuder-Richardson 20) 0.819 ve tutum ölçeğinin güvenirlik katsayısı (Cronbach Alpha) 0.946 olarak bulunmuştur. Araştırmanın nitel verileri ise deney grubu sınıf öğretmeni ile uygulama sonrası yapılan görüşmeden elde edilmiş olup verilerin içerik analizi yapılmıştır. Araştırma sonuçlarına göre, geliştirilen sayı şeridi materyalinin anlatılan konuyu somutlaştırıp basitleştirdiği, derse karşı ilgi ve merak uyandırdığı, derse karşı öğrencilerin aktif katılımını sağladığı, dersi zevkli ve eğlenceli hale getirdiği, öğrencilerin matematiğe karşı tutumlarını olumlu yönde etkilediği ve öğrencilerin başarılarını artırdığı söylenebilir

In our rapidly developing and changing world, the information is outdated pretty quickly and it became important to teach children how to obtain information instead of memorization. The global advances introduced significant changes and advances in the field of education. Learning and teaching models that were based on conventional approaches and aim the memorization of the existing information are abandoned and student-centered constructivist models that enable the student to access the information are adopted (İnan and Erkuş, 2016). In the implementation of the new learning and instruction methods, instructional materials that could simplify difficult learning and allow the active participation of the students are required. When the fact that primary and middle school children could learn more rapidly and permanently with concrete experiences is considered, it is especially important to use material that concretize the topics in instruction. Pre-service teachers observed that students had difficulty placing numbers in the numerical order and determining the decimal number digits during their internship in the school experience course. To overcome this difficulty, the idea to develop a material was discussed with pre-service teachers in the mathematics instruction course and the discussions resulted in the idea of developing a number strip material on which operations could be conducted. The developed number strip material allows the numbers to be placed on the numerical axis by dividing the axis into equal parts. In mathematics, the location and operation of the numbers is important. The mistakes made about numbers when solving problems often make it difficult to solve the problem. Would the success of the student who recognizes that the negative of a number is in fact the same distance reversed on the numerical axis, a decimal is the division of the distance on the numerical axis by ten and a percentage is the division of the distance by a hundred change? Literature review demonstrated that material such as a history strips are available, however no material similar to number strip that examined the locations of numbers was found. Thus, the present study aimed to find answers to the following questions: 1. Does the developed number strip material affect students' mathematical achievements? 2. Does the developed number strip material affect students' attitudes towards mathematics? The study utilized a mixed methodology that combined qualitative and quantitative research methods. The study sample included 86 (43 study group and 43 control) 4th grade students who were attending a primary school in the Bağlar district in Diyarbakır province during the 2016-2017 academic year. The achievement test and attitude scale developed by the author were used to collect the study data. The achievement test and attitude scale were applied as both pretest and posttest to the control and study groups. The data obtained were analyzed with SPSS 24.0 software and it was determined that the achievement test reliability coefficient (Kuder-Richardson 20) was 0.819 and attitude scale reliability coefficient (Cronbach Alpha) was 0.946. The qualitative data were obtained with the interview conducted with the classroom teacher after the application, and content analysis was conducted on the data. Pre-test achievement scores of the control and study group students demonstrated that there was no significant difference between the pre-test scores of these groups [t(84) = -.210; p> 0.05] in the conducted independent groups t-test results. The pre-test mean achievement scores of control and study groups showed that these scores were quite similar (?̅ control = 52.09 and ?̅study = 53.26). Thus, the fact that there was no significant difference between independent t-test results and pretest mean achievement scores were close in both groups demonstrated that the students had similar prior knowledge. The posttest achievement scores of control and study group students demonstrated that there was a significant difference between the posttest scores of these groups [t(84) = -2.333; p 0.05] in the independent t-test. The pre-test mean attitude scale scores of control and study groups showed that these scores were quite similar (?̅ control = 2.89 and ?̅study = 2.95). Thus, the fact that there was no significant difference between independent t-test results and pretest mean attitude scale scores were close in both groups demonstrated that the students had similar attitudes towards mathematics. While there was no significant difference [t(42) = -.981, p> 0.05] between pretest and posttest attitude scores of the control and study groups based on the dependent groups t-test results that was conducted to determine the attitudes of the students before and after the application, there was a significant difference between the pretest and posttest attitude scores of study group students [t(42) = -11.014, p