Quantum computers aren't intended for general purpose computing or math operations
Not entirely true. There is a lot of work being done on general purpose quantum computing architectures at the moment. In fact there are already some quantum compilers out there such as http://tph.tuwien.ac.at/~oemer/qcl.html. Also, a number of algorithms do actually require math operations to be performed by the quantum processor. Remember that measuring a qubit collapses its wavefunction so it is often important to do math operations on qubits before they are measured.
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