I think this is a great lesson plan because it uses math in a real world context. Too often students don't see the connection between what they are learning in class and how it can help them in the real world. By analyzing serving sizes while using fractions, students will be able to see the practicality of this task. It also sounds like it builds on students' prior knowledge of multiplying and dividing whole numbers, as well as their knowledge of fractions. This sounds like a fun activity to put that knowledge to use. Great job!