you should do what works best for you, if you have an event coming up that week use them then or if you are a little extra hungry a few days then divide them up or a lot hungry one day use them all at once. I'm counting calories now but when i was on WW i also used all my flex and all my activity points (i like to eat) and i lost a couple pounds at least every week. every one is different though so try it out and see what happens. good luck!
I have only used all but 3 one time (I goofed and pigged out on pizza), other than that I usually have about 25-30 left each week. I lost weight both weighs, but when I only had 3 left I felt pretty stressed as to whether or not I was going to gain that week. I prefer to have them as a back up. Quite often when I do use them it's only 1-2 added on to a day to have an extra something.