Building on her students experience with the Similar Triangles on the Same Line task, Marcelle (the teacher), engages students in exploring the mathematical concept of slope through the use of slope triangles.

# Slope/Y-Intercept

## Revisiting Angel’s Question

As students discuss a variation of the Growing Dots task in which the starting point is shifted, one student shares that when the first dot is at time 0, the rule is 4x – 3. Another student, Angel, asks, “Where is the –3 in the picture?”

## Angel’s Question

As students discuss a variation of the Growing Dots task in which the starting point is shifted, one student shares that when the first dot is at time 0, the rule is 4x – 3. Another student, Angel, asks, “Where is the –3 in the picture?”