8th Grade Math Intervention Resources to Support Unit 2: Dilations, Similarity, and Introducing Slope

A growing list of resources to use during an intervention block to support kids with grade level work. I’m trying to collect a mix of activities to support practice, conceptual understanding, vocabulary, and synthesizing big ideas.

Dilations and Similarity

Desmos Polygraph
Great game for reinforcing vocabulary related to all transformations. 
Desmos: Dilation Mini Golf
Kids explore dilating a point from a point. Great for reinforcing that scale factor is how many times farther a point is from the center of dilation.
Desmos: Sketchy Dilations
From the description: “In this lesson, students are informally introduced to dilations through experimenting with “sketching machines” that allow them to adjust various parts of a drawing to see the effect on the pre-image. Students are then introduced to similarity as the result of a dilation.”
Desmos: Transformation Golf Non Rigid Transformations
In the style of rigid transformation golf…but includes dilations!
Prove Similarity
Kids practice describing a sequence of transformations (on the coordinate plane) that proves two figures are similar. (Tracing paper would make this much more enjoyable!)
Drawing Dilations with Different Centers
Give kids more time to explore the impact of the location of the center of dilation.
Comparing Dilations to Rigid Transformations
A synthesizing activity to give kids the opportunity to name what they have learned about dilations and rigid transformations by comparing the two.Could let kids do a brain dump where they write as much as they can independently and then have them pair up and add to their lists and then group up and add even more. 


IM Unit 2 only exposes kids to lines positive slopes, so these first two activities could be used to pre-teach the idea of negative, zero, and undefined slope if that feels right for your students, or save them for Unit 3!

What is Slope?
Kids create a definition from looking at examples and then practice finding the slope.
Source: Mathequalslove
Slope Dude
A memorable video about positive, negative, zero, and undefined slopes. Preface with how “cringe” it is and kids seem to embrace it.

Desmos: Water Slide
Kids use the idea of similar triangles to create a smooth ride.
Desmos: Which is Steepest?
Kids explore the idea of steepness and in doing so are prompted to think about measuring slope. 

Mixed Review

Mixed Review Problems
Could cut up and let kids pick the topics they need to practice.

Please let me know what’s missing!


Always happy to hear from readers!