How close can a math simulation come to predicting a real rocket flight? You calculate expected altitude and speed for six model rockets using physics equations. The equations account for thrust, drag, mass, and gravity. Then you launch each rocket and measure its actual altitude and flight time. You use altitude finders and stopwatches to record the real values. The simulation predictions land within 20% of the measured results. Math-based models can give a reliable picture of how a model rocket will fly before you ever light the engine.