Begin teaching the difference between mixtures and solutions by explaining the difference to the class using chocolate milk as an example of a mixture and lemonade made from a mix as a solution. Demonstrate the concept by mixing sand, salt and vegetable oil with water in three separate containers. Ask the class to identify whether each one is a mixture or a solution.
Explain how changing phases of matter can help to separate the ingredients. Discuss real-life applications that involve creating and separating mixtures and solutions, such as making gasoline and cleaning up oil spills. Close the lesson by asking questions about each stage of the lesson.
TeachEngineering.org includes a list of vocabulary terms related to the topic, along with assessments and extension activities. The extension activities include having the students list examples of mixtures and solutions that they can find around the school or their homes.
A lesson plan at BrightHubEducation.com suggests having students work in small groups to create and separate various mixtures. Assess how well the groups can separate the mixtures, and have students identify mixtures and solutions from pictures. As an extension activity, brainstorm methods for separating solutions such as evaporating water by adding heat.
A video of a lesson on the subject is available at UCSC.edu. The video is of a 5th Grade class in Georgia, and shows the teacher introducing the concept to the students before leading a lab activity.