Students will explore the idea of scaling in tandem with a ratio as a composed unit.

Intentionality…

In this assessment, students will have an opportunity to demonstrate and apply their understanding of working with a ratio as a composed unit. This assessment can elicit the following big ideas although they may not all be present in every student’s solutions:

• Unitizing;
• Ratio reasoning through scaling in tandem;
• The relationship between repeated addition and multiplication;
• A composed unit is one way of defining the relationship that exists in a ratio.
• Numbers can be composed and decomposed.
• There is a constant multiplicative comparison that exists between two quantities in any ratio that is derived from the same rate.
• The distributive property of multiplication over addition and subtraction.