Entering unknown calories burnt from exercise in MyFitnessPal

Here is a tip for anyone using MyFitnessPal to track calories.
 If you are exercising and don't know how much calories you burnt, try to put a small number for the exercise, this way mfp will only ask you to eat that much extra calories and you don't end up eating more.

Explanation: 

MFP calculates calories required as Calories Needed = Calorie Intake + Calories Burned with exercise. what it means, if your calorie target is 1800 calories and you did not do any exercise then you'll need to eat 1800 calories.
i.e. Calories Needed = 1800+0 = 1800.
If you worked out and burnt 100 calories then 
Calories Needed = 1800+100 = 1900.

So the point is, if you dont know how much calories you burned, then putting a small number is better (for weight loss), that way MFP doesn't bump up the calorie needed.