This activity involves the following skills: addition, subtraction, multi-step problems, problem solving, regrouping, place value, and higher order thinking. You can allow students to solve these problems in small groups or individually. I think it would work best if you allow students to work in groups and to talk about their strategies and defend their answers and reasoning. Allow them to talk about strategies with one another and defend their arguments.
The questions included have rigor and allow students to really think about how to get the answer.
Allow students to determine whether other students' answers are correct or incorrect and show each other why. Try not to interrupt their demonstrations so that they learn that they are in charge of their thinking and that the teacher is not always the source for the correct answer.
*These are not real caloric amounts and all reference to name brands are for the purpose of this activity, not to promote any products