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 1: Make 5
Required Preparation
Materials to Gather
5-frames
Counters
Number cards 0–10
Materials to Copy
Blackline Masters
Find the Pair Stage 1 Recording Sheet

Narrative
Before playing, students remove the cards that show numbers greater than 5 and set them aside.
Partner A asks their partner for a number that would make 5 when added to the number on one of their cards. If Partner B has the card, they give it to Partner A and Partner A gets a match. If not, Partner A chooses a new card. When students make the target number 5, they put down those two cards and write an expression to represent the combination. Students continue playing until one player runs out of cards. The player with the most pairs wins.


aligns: no