This study aimed to determine the initial conditions of mathematics learning using worksheet, worksheet development, student responses, teacher responses, supporting and inhibiting factors for using the worksheet, and the effect of using mathematics worksheet on the circumference and area of plane figure using a calculator with Delikan learning in grade IV of SD UMP. This study used the Research and Development (R&D) method of the Borg and Gall development model. The worksheet that had been used in learning mathematics in grade IV of SD UMP was a worksheet taken from the textbooks. The result of the validation using three validators obtained an overall average value of 4.16 with valid criteria. The trial of worksheet was carried out based on the Delikan learning steps. Delikan is a learning method involving listen (DEngarkan), see (Llhat), and do (kerjaKAN). The result of students response questionnaire was 4.58 with very good criteria. The teachers questionnaire response to the mathematics worksheets obtained a result of 4.2 with a good category. The developed worksheet received a
very good response from students because the use of calculators was something new, but there were some students who did not understand the concept of multiplication and long division so they needed guidance from the teacher. The
results of the pretest and posttest analysis using SPSS indicated that the use of student worksheets brought an effect on student learning achievement. Mathematics worksheet on circumference and area of plane figure using a
calculator with Delikan learning in grade IV of SD UMP is said to be feasible and can be used as an alternative to improve skills in calculating circumference and area of plane figure using calculators.