Uh........don't you think you're a little late on this one?
You need to review your textbooks and go back over your own notes to find the formulas, then do some practice calculations until you are sure of yourself. I'm serious. This basic knowledge is too vital to blow off until two days before sitting for the NCLEX; in case you didn't know already, every math mistake in nursing is a MED ERROR, and every med error is a potential disaster, not only for the patient but for the nurse who faces liability issues, license suspension/revocation, and loss of their livelihood.
Get with it, and learn those calculations yourself.........you owe your future patients nothing less. :stone