When working with short sound waves there are sometimes waves that are 0.23 milliseconds of a second and even lower 0.041 milliseconds of a second. In seconds they are 0.00023 sec. and 4.1e-5 sec. They are also 230 microseconds and 41 microseconds of a millisecond.
How do we pronounce these fractions?
A second has 1000 milliseconds. A millisecond has 1000 microseconds.