The simple and embarrassing fact is that none of the responses have hit the target of the question.
The result is buried in another parameter that is supplied in the data sheet: the sensitivity.
for example the FXAS21002C for 2000 dps sensitivity is 62.5 mdps/LSB (=0.0626 dps/LSB).
the zero offset is 25 LSB thus the value in dps units is 0.0625 * 25 = 1.5625 dps
the same IMU has another sensitivity for 250 dps which is 7.825 mdps/LSB (=0.007825 dps/LSB) and since the offset is also 25 LSB then the calculation will expose the real value of 0.0078125 * 25 = 0.1953 dps
the example can be found here: https://learn.adafruit.com/comparing-gyroscope-datasheets/overview
