## Lesson Seed A.2: Calculator and Direct Variation

**Essential Questions: **

**Lesson Plans and Seeds**

Lesson Plan A.2: Proportional Relationships and Similarity

Lesson Seed A.2: Creating a Graph from a Table

**Lesson Seed A.2: Calculator and Direct Variation**

**Download Seeds, Plans, and Resources (zip)**

**Content Emphasis By Clusters in Grade 7**

**Progressions from Common Core State Standards in Mathematics**

Lesson seeds are ideas that can be used to build a lesson aligned to the CCSS. Lesson seeds are not meant to be all-inclusive, nor are they substitutes for instruction. When developing lessons from these seeds, teachers must consider the needs of all learners. It is also important to build checkpoints into the lessons where appropriate formative assessment will inform a teachers instructional pacing and delivery..

**Standard(s): 7.RP.A.2 **Recognize and represent proportional relationships between quantities.

**Purpose/Big Idea: **

- Investigate direct variation to decide whether two quantities are in a proportional relationship by testing for equivalent ratios in a table or graphing on a coordinate plane; identify the constant of proportionality (unit rate) in tables and graphs of proportional relationships.

**Materials:**

- Graphing calculator – preferably TI-83 Plus Family & TI-73 Explorer

**Activity:Exploration**

- Using a graphing calculator, students will solve problems involving direct variation and will identify relationships among values through the use of tables, scatter plots, and graphs on a coordinate plane; and students will apply direct variation, proportion, and percent to authentic scenarios.

**Resource:**

https://education.ti.com/educationportal/sites/US/sectionHome/classroomactivities.html

**Guiding Questions:**

- What does “direct variation” mean?
- How does the concept of “direct variation” relate to or exemplify a ratio or a proportional relationship?
- What is the constant of proportionality (unit rate) for a given data set?
- When given data set is graphed on a scatter plot, what is the relationship between the resulting points?
- How does this relationship relate to a ratio? To a proportion? To a unit rate?