standard_description: Prove that, given a system of two equations in two variables, replacing one equation by the sum of that equation and a multiple of the other produces a system with the same solutions.
problem_activity: Stage 1: Add
Required Preparation
Materials to Gather
Connecting cubes
Counters
Materials to Copy
Blackline Masters
5-Frame
Number Mat 1–5
5-frames Stages 1 and 2 Recording Sheet

Narrative
Students begin with a full 5-frame and roll to see how many counters to add.


aligns: no