Facebook notifications on iPhone? - 1

On my Facebook application on my iPhone I always have a red number 3 or 4 on the corner of it, expecting to have that amount of notifications when i go on but it turns out I only have 1 each time, why is this! It's annoying

I too faced the same problem. Sometimes the notification is about a post you have tagged, so whenever people comment on the post you will get notification. The number will increase based on the peoples' comments but only one notification will be there.