I thought about this:
You know how you have , Sharing, Comments, Forums, Friends, and Special Badges in levels 1-5/6? Well, I was thinking that at the end of each one (Where it says you have to post 50 comments etc.) That there would be a meter to tell you how many you have left to post/share.
Kind of like "Congratulations! You earned the Level 2 Comments badge for commenting 500 times on Kidzworld. (200 Left)"
Worth a shot -