  We calculate tree level scattering amplitudes for open strings using the NSR
formalism. We present a streamlined symmetry-based and pedagogical approach to
the computations, which we first develop by checking two-, three-, and
four-point functions involving bosons and fermions. We calculate the five-point
amplitude for massless gluons and find agreement with an earlier result by
Brandt, Machado and Medina. We then compute the five-point amplitudes involving
two and four fermions respectively, the general form of which has not been
previously obtained in the NSR formalism. The results nicely confirm
expectations from the supersymmetric $F^4$ effective action. Finally we use the
prescription of Kawai, Lewellen and Tye (KLT) to compute the amplitudes for the
closed string sector.
