// Scilab code Exa1.4.1: To calculate the energy of electron at rest : Page 33 (2011)
m = 9.1e-031; // Mass of the electron, Kg
C = 3e+08; // Velocity of the light,m/s
E = m*C^2/1.6e-013; // Energy of the electron at rest, MeV
printf("\nEnergy of the electron at rest : %5.3f MeV", E)

//   Result
//    Energy of the electron at rest : 0.512 MeV