Hey MadkingPercy,
Make sure that your new progress bar is both valid (as in your cast is successful and you can get that value - such as health) as well as when you divide it, its result is a floating point number (like the screenshot above) and it is from 0.0 to 1.0.
If you can, please post a screenshot or more information related to how this new progress bar may be different from the health bar.