# Manipulate: Show result in Engineering/Scientific Form

I have a simple definition as follows and the result expected is in either EngineeringForm or ScientificForm

DurationOfAcquistion[RatePerSec_, RecordLength_] :=
EngineeringForm[RecordLength/RatePerSec];

DurationOfAcquistion[20.*10^6, 1000] (* results in 50.x10^-6 *)
Manipulate[
DurationOfAcquistion[r, rl], {r, 20*10^6, 1.25*10^9}, {rl, 1000,
125*10^6}]


When I deploy the same function definition using Manipulate, I can't seem to get it in either Engineering/Scientific form. I am currently using MMA 11.3 release. Can someone please confirm if this is how it's supposed to be or is there an alternative way?

EDIT

I really have to apologize, this may be like a bug in output format display, but not a serious one. I was able to see the output in EngineeringForm once I started manipulating the sliders >>> Please watch the GIF here.

You need to make the initial value of r or rl a real, instead of an integer (otherwise the initial value of rl / r will be a rational). For example:

Manipulate[EngineeringForm[rl / r],
{r, 20.0*10^6, 1.25*10^9},{rl, 1000.0, 125*10^6}]


In this case the initial values of both r and rl are reals, but you only need to make one of them real.

Manipulate[N @ DurationOfAcquistion[r, rl], {r, 20*10^6, 1.25*10^9}, {rl, 1000, 125*10^6}]


Alternatively, change the right-hand-side to

EngineeringForm[1. RecordLength/RatePerSec]


when you define DurationOfAcquistion.