Unit 2, Lesson 5
Defining Equivalent Ratios
Grade 6
Preparation
Lesson Narrative
In this lesson, students work with equivalent ratios more abstractly, both in the context of recipes and by using numbers without a context. They learn and articulate that all ratios that are equivalent to can be generated by multiplying both and by the same number.
As they connect concrete quantitative experiences to abstract representations, students develop their skills in reasoning abstractly and quantitatively (MP2). They continue to use diagrams, words, or a combination of both for their explanations.
- Generate equivalent ratios and justify that they are equivalent.
- Present (in words and through other representations) a definition of "equivalent ratios," including examples and non-examples.
Let’s investigate equivalent ratios some more.
Required Materials
Activity 3
Required Preparation
None
Extend the lesson during the Activity Synthesis of Activity 3, “What Are Equivalent Ratios?,” by explaining to students that the axolotl (ACK-seh-loh-tihl) is critically endangered in the wild and faces an extremely high risk of becoming extinct. Review the meaning of each term:
- endangered (There are not many living individuals of a species because of loss of habitat or threats to its population.)
- extinct (There are no living individuals of a species left on Earth.)
Explain that the main threat to the axolotl is habitat loss due to urban development, drought, water pollution, and climate change. Ask: “Which of these causes of habitat loss do you think is a result of human activities?” (urban development, water pollution, climate change)
Emphasize that, although the climate changes naturally on its own, human activities are causing an unnatural increase in global warming (the long-term warming of the planet).
Ask students to share examples of human activities that affect Earth’s climate. Students may give examples such as burning fossil fuels, cutting down forests, and farming livestock—all of which release greenhouse gases into the atmosphere, gradually warming the planet over time.