<![CDATA[21st-century education requires students to master creative thinking skills, including in mathematics learning. However, preliminary observations in grade V of MI Darul Muta'allimin Cepoko showed that students' mathematical creative thinking ability was still low because learning tended to be teacher-centered and demanded a single method of solving problems. This study aimed to examine the effect of the RICOSRE learning model (Reading, Identifying the Problem, Constructing the Solution, Solving the Problem, Reviewing the Problem Solving, and Extending the Problem Solving) on students' mathematical creative thinking ability in the topic of whole numbers. This study used a quantitative approach with a quasi-experimental method and a nonequivalent control group design. The subjects were 32 fifth-grade students selected through purposive sampling, consisting of an experimental class (16 students, treated with the RICOSRE model) and a control class (16 students, conventional learning). Data were collected through essay tests (pretest and posttest) and a student response questionnaire, then analyzed using the Shapiro-Wilk normality test, Levene's homogeneity test, the Independent Samples T-Test, and simple linear regression with SPSS. The results showed that the experimental class's posttest mean (87.19) was higher than the control class's (79.69), with a t-test significance value of 0.004 (p < 0.05). The regression analysis produced the equation Y = 24.311 + 0.710X with a significance of 0.006 and a coefficient of determination (R Square) of 0.433, meaning the RICOSRE model contributed 43.3% to students' mathematical creative thinking ability. It is concluded that the RICOSRE learning model has a positive and significant effect on the mathematical creative thinking ability of fifth-grade students in the topic of whole numbers.]]>
