standard_description: Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line in the coordinate plane; derive the equation y = mx for a line through the origin and the equation y = mx + b for a line intercepting the vertical axis at b.
problem_activity: Stage 2: Numbers 11 - 20
Required Preparation
Materials to Gather
Colored pencils, crayons, or markers
Connecting cubes
Materials to Copy
Blackline Masters
Number Mat 11–20
Number Race Stage 2 Recording Sheet for Writing
Number Race Stage 2 Recording Sheet for Tracing

Narrative
Students take turns rolling a connecting cube onto a number mat and write the number (11–20) they land on, on the recording sheet. Students may want to use colored pencils to write the numbers.
Variation:
Students may use the blackline master that allows them to trace each number to support their number writing skills.
Additional Information
Each group of 2 needs 1 connecting cube.


aligns: no