Slope–Intercept Explorer
A slope intercept explorer for an interactive y = mx + b graph. Drag the intercept and a second point anywhere on the grid. Snap to whole-number points, read signed rise and run, and see undefined slope on a vertical line. Compare a second line, or match a dashed target. Free, no login, ready for a classroom projector.
Who·Algebra 1 on a projector or iPad
Teacher tip
Project this page and tap Full screen. Explore opens on y = 2x + 1, with a rise 4, run 2 triangle — the same slope as 2. Drag the blue point anywhere on the grid, including left of the y-axis: run shows a minus when the point is to the left. Drag it straight above or below the intercept and the line is vertical, x = 0, with undefined slope. Snap lands on whole-number points. Compare adds a second line. Match asks the room to cover the dashed line; its equation stays hidden until the two agree. One idea fits in five minutes. See every lab on Math Labs.
Drag the point on the y-axis, or the blue point anywhere on the grid.
Equation
y = 2x + 1
Slope m
2
Intercept b
1
Slope 2, intercept 1. y equals 2 x plus 1. Rise 4, run 2.
Drag either point, or use the sliders. Arrows move the focused point. A point on the y-axis makes a vertical line. Escape resets the lab.