another student

I have an IV question that I was hoping you all can answer. We are doing pediatrics right now (I am a student) and they are doing the math for IV's. Since the amounts of the medication is is so small for peds I understand that you have to make sure to flush the tubing. My question involves the rate in which they infuse the medication. We figure out the exact amount of medication that we have to infuse, say 10ml. Then instead of calculating the rate based on that, say it is supposed to be infused over 1 hr, they say we should add the volume of the flush as well, 10 ml meds +5ml flush over the same time period. Isn't this going to be too fast of an infusion rate if it is supposed to be infused at 10ml/hr? Why wouldn't you just set the rate at 10 ml/ hr and then just put the volume to be infused as 15 ml? Isn't 15 ml/ hr going to be too fast? I am hoping that you all can explain this for me.