standard_description: Prove the slope criteria for parallel and perpendicular lines and use them to solve geometric problems (e.g., find the equation of a line parallel or perpendicular to a given line that passes through a given point).
problem_activity: Fill out the following chart.
| **           Standard form          ** |  **           Unit form          **  | **           Expanded form          ** |
|----------------------------------------|--------------------------------------|----------------------------------------|
|                                        |                                      |            5,000 + 400 + 3             |
|                                        | 8 thousands 6 hundreds 3 tens 2 ones |                                        |
|                 2,061                  |                                      |                                        |


aligns: no