What students learn
Every pass is a line. The ball starts at the y-axis, and the student types the slope (as a fraction, rise over run) and the y-intercept of the line that reaches a teammate or the goal. The line appears on the field, and the ball follows it.
- Slope m is rise over run, typed as a numerator and a denominator, with a key to make it negative.
- Y-intercept b is where the line crosses the y-axis. Every pass starts at x = 0, so the ball's own position is (0, b). A wrong intercept is caught immediately because the line starts in the wrong place.
Modes and support levels
- Proportional mode fixes b = 0, so every line is y = mx through the origin. Start here.
- Non-Proportional mode adds a real y-intercept: y = mx + b.
- Easy previews the line while students type it, so they can adjust. Hard hides it until they kick.
- Play the computer, a friend on the same device, or a full tournament bracket.
Worked examples
Proportional pass: from the origin to a teammate at (4, 6)
m = rise / run = 6 / 4 = 3/2 → y = (3/2)x
Non-proportional shot: the ball is at (0, 2) and the goal is at (6, −1)
b = 2 m = (-1 - 2) / (6 - 0) = -3/6 = -1/2 y = -1/2 x + 2
Common mistakes
Run over rise (typing 4/6 instead of 6/4). The line comes out too flat, and students see the ball miss low.
Forgetting the negative on a line that goes down to the right. The line tilts the wrong way on the field.
Using the target's y-value as b. Because the ball sits at (0, b), a wrong intercept starts the line away from the ball, which makes the meaning of b concrete.
Ways to use it in class
- Printables. A free worksheet with an answer key and a two-to-a-page exit ticket match this game, ready to print or save as a PDF.
- Launch slope. Project Proportional mode on Easy. Ask the class to call out a slope, watch the line, and adjust together.
- Progression. Proportional/Easy → Proportional/Hard → Non-Proportional/Easy → Non-Proportional/Hard.
- Tournament day. Run a class bracket in pairs for review.
- Show your work. Students record each pass as two points and the equation they wrote.
- Exit ticket. "The ball is at (0, −3) and the goal is at (4, 5). Write the equation of the shot."
Discussion questions
- What happens to the line when you make the slope bigger? Negative? Zero?
- Why does every proportional line pass through the origin?
- Two passes have the same slope but different intercepts. What do their lines look like?
Real-world connections
Any situation with a constant rate and a starting amount is a line: a taxi fare with a base charge plus a cost per mile, a phone plan, or the grade of a ramp or road. The starting amount is b and the rate is m.
Standards
CCSS.MATH.CONTENT.8.EE.B.6Use similar triangles to explain why the slope m is the same between any two distinct points on a non-vertical line; derive the equation y = mx for a line through the origin and y = mx + b for a line intercepting the vertical axis at b.
Access and privacy
No accounts, no data collected. Students type with the keyboard or use the on-screen number pad on a tablet.