Need help with recipe

In my recipe, I use 5 ⅓ cups of milk for the sauce. I'm not sure if wording it like "5 ⅓ cups" is correct or if that might be confused as saying 5 cups AND ⅓ cup. I also want to make it clear in the instructions that I pour this amount in ⅓ cup at a time and stir before adding the next, so that the milk is slowly stired in. Not sure how best to do this.