To calculate real GDP growth when nominal GDP grows by 7% and inflation is 2%, the simplest method is to subtract the inflation rate from the nominal growth rate, resulting in a real GDP growth of 5%. A more precise calculation involves adjusting for inflation, yielding a real GDP growth rate of approximately 4.902%. The discussion emphasizes that for small values of growth and inflation, the simpler subtraction method is adequate. However, the more complex formula accounts for the interaction between growth and inflation. Ultimately, both methods provide insights into real GDP growth, with the latter being more accurate for precise economic analysis.