The students start the numerical calculation by guessing the first date of the first infectious person in a state, e.g., five days before the first date of report. The student can practice manual fitting by changing Rt values piecewise as explained previously by comparing the simulated new cases per day with the raw data. They can also directly calculate the real-time Rt and Re values by estimating β from Equation 15 by replacing the simulated new case with the smoothed raw data of daily case, newIraw: