Scientific pitch is a concert pitch standard in which middle C is set to 256 Hz. This is in contrast to the commonly used standard pitch in which the A above middle C is set to 440 Hz and thus middle C becomes 261.62 Hz. Although not used by orchestras, it is sometimes used for convenience in scientific writings because all octaves of C become an exact round number in the binary system when expressed in Hertz and remain a whole number in Hertz all the way down to one Hertz in both the binary and the decimal systems.