Hunger pains are pains you get in your belly. They sometimes feel like cramps or someone pushing or pulling on your belly. It's your body telling you it needs food.
It depends on what you want. Hunger pain is a pain in your stomach that won't go away until you are fed. A hunger pang is a brief, sharp, intense pain that lasts seconds or less because you are...
well, when my stomach rumbles i punch myself in the stomach and it stops making that aweful noise. But for pain i find curling up into a ball and hugging your knees to your chest helps :)