The unit rate of anything is a comparison of two different quantities, such as 25 miles per one hour. Like in miles per hour, you want to get one of the numbers to be one. In this case, you will want to get servings down to one because there are 1760 calories per 8 servings.
The math part is pretty simple. You just divide 1760 by 8. You will get 220. This is the amt of calories in each serving.
There are at least 3 ways of writing it: 220:1 or 220/1 or 220 to 1
Use which ever way is familiar(:
I hope this helped, and feel free to ask more questions if you need!! (: