Lesson objective: Understand that we need two pieces of information to designate a position on the coordinate plane.

Students bring prior knowledge of plotting points in Quadrant I. This prior knowledge is extended to all four quadrants of the coordinate plane as students plot points that include negative rational numbers. A conceptual challenge students may encounter is inverting the (x, y) structure of the coordinate pair or confusing the x axis' horizontal nature with the y-axis' vertical nature .

The concept is developed through work with the four quadrants of the coordinate plane, which allows students to physically see the movements along the x and y axes while plotting points.

This work helps students deepen their understanding of number lines and positive and negative rational numbers because they are extending horizonal *and *and vertical number lines to help them find a designated position on the coordinate plane that they form.

Students engage in Mathematical Practice 7 (look for and make use of structure) as they apply their knowledge of coordinate pairs and how they relate to an x and y-axis that have been extended to include negative values.

**Key vocabulary:**

- coordinate plane
- quadrant
- vertex
- x-axis
- y-axis

**Special materials needed:**

- scrap blank coordinate planes