Can someone explain the Burn Meter to me?

Hi! I'm new on here and I don't quite understand how the Burn Meter works.  I don't understand why adding activites doesn't seem to raise the levels. And I don't get how I can plan how much I need to exercise using that meter. Thanks for your help!

The Burn Meter shows you the number of calories that your body burns as the day goes on (not including any extra activity that you may do during the day). 

It tell you how many calories you can consume through out your day to maintain your weight. Any extra exercise that you do will burn more calories and help you lose weight, also by keeping your calorie intake lower than your burn meter will help with weight loss. 

Hope this helps a little