Juita, NurmaImran, M.Kho, Johannes2013-03-162013-03-162013-03-16Rangga Dwijunanda Putrahttp://repository.unri.ac.id:80/handle/123456789/2614This paper discusses the Runge Kutta method of order-4 (RK (4,4)) with an error control, which is a combination of the Runge Kutta method of order-4 based on an Arithmetic mean (RKAM-4) and the Runge Kutta method of order-4 based on a Contraharmonic mean (RKCoM-4). Difference between approximation of RKAM-4 and RKCoM-4 is used to control the step length of the method. So the RK(4,4) is a method with a variable step length, as well as the Runge Kutta Fehlberg 4(5) (RKF4(5)). Numerical computation is also done in four cases, which are then compared with RKF4(5). The results show that the behavior of RK (4,4) is similar to that of RKF4(5)otherRunge Kutta method of order-4Runge Kutta Fehlberg 4(5)Arithmetic meanContraharmonic meanOther