A couple things. My personal preference is to always use a double. I know it is double the space, but it is far more precise. Next, you do not have to use the [NSString stringWithFormat] inside NSLog. You can do this:
Code:
NSLog("Percent = %.2f", percent);
Last thing, how do you assign the value of percent. It sounds like the conversion is not properly done. Post your code for how percent is assigned its value.