This research aimed to improve curiosity and mathematics learning achievement through Think Pair Square cooperative learning model. This was a classroom action research consisting of two cycles. The subjects of this research were 23 fourth graders of SD Negeri 2 Kebakalan consisting of 13 male students and 10 female students. The instruments of this research were the observation sheets of teacher's and students' activity, observation sheet of students' curiosity, questionnaire, and evaluation sheet. The average score of students' curiosity in cycle I was 3.22 and improved to 3.26 in cycle II that was also supported by the improvement on the observation result of students' curious behavior which was 53% in cycle I and improved to 69% in cycle II which meant the students' curious behavior had already been good in the learning process. Another improvement was also showed on the students' mathematics learning achievement which was 76.05 with 78% of completeness in cycle I to 77.05 with 86% of completeness in cycle II. The results showed that Think Pair Square cooperative learning model that was supported by tablecloth for four people was able to improve the students' curiosity and mathematics learning achievement on angle measure on the fourth grade of SD Negeri 2 Kebakalan, Mandiraja Sub-district, Banjarnegara Regency