Ok, another loonie question...
If you dont take in(food) more than you burn (exercise),how can you tell how much food do you eat daily and not exercise and gain weight?

I just take weight and multiple by 10- if you eat over that most likely you'll gain weight. So for me- right now if I eat over 1920 calories a day I'll gain.

I'm not sure if that's what you are asking- you can also look up your basal metabolic rate to get an idea of where you should be targeting.