The purpose of this paper is to identify the advantages of including a floating point hardware / a mathematical co-processor in microcontrollers used for critical floating point operations. Three different microcontrollers are considered: Renesas M16C/62P (CISC without FPU), ATMEGA1280 (RISC without MCU) and Renesas RX62N (CISC with FPU). Gauss-Seidel and Jacobi iterations for a system of 2 and 3 variables using single precision and double precision floating point numbers are implemented. The time taken by each microcontroller is measured using the Timer in the microcontrollers. Based on the time taken, the advantages of the inclusion of the floating point unit are attributed against the cost incurred by the hardware.