This is a hands on learning activity where students create three different solutions. First, they observe the physical properties of the ingredients. Then, they mix the ingredients and observe if the physical properties change or stay the same. Next, they must create a plan to separate the solution.
This lesson seems to work best in small groups. I also always have a lot of filters available because students think that the filter can catch the salt and sugar. I allow them to discover that it can not on their own. I also make sure that I call the solutions "mixture/solutions" to remind the students that solutions are fancy mixtures.