Projection formulas from the interacting boson model-2 to the interacting boson model-1 are given for a rather general class of operators and numerical tests of these formulas were carried out with the corresponding codes. Agreement of energies and B(E2) values of the interacting boson model-2 calculations with those of the interacting boson model-1 calculations, where the interacting boson model-1 parameters are yielded with the projection formulas, to better than 0.1% was found for sufficiently large values of the Majorana parameter.