Draw Your Track: Staggers for a Schoolyard Curve

Groups chalk a four-lane curve in the schoolyard using a rope as a compass and calculate the stagger each lane needs so everyone runs the same distance. To finish, they test their track with a race around the curve.

How to play

1. Explain why outside lanes start farther ahead: the length of a semicircle grows with its radius (4 min).
2. With a rope anchored at a center point as a compass, each group draws a half curve of four 1-meter lanes with radii of 10, 11, 12 and 13 m (8 min).
3. Groups calculate each lane's stagger relative to lane 1 by multiplying pi by the difference in radius, then mark it with chalk and a cone (6 min).
4. Track test: four runners race around the curve and a judge checks whether they finish even (8 min).
5. Review the measuring errors found and how to fix them (4 min).

Rules

• Tape measures and ropes are picked up before running so nobody steps on them.
• Only four students run at a time during the test, at a controlled 80% pace.
• The student holding the center of the rope doesn't move until the curve is finished.
• Draw the track in a part of the schoolyard where other groups aren't passing through.

Variations

Adaptations

• Limited mobility: anchors the compass center and handles the group's calculations.
• Dyscalculia: gets a table with pi already multiplied by each difference in radius.
• Autism: has a specific, continuous task, such as placing a cone every 2 m along the curve.

Learning goals

• Understand the math behind staggered starts in curved races.
• Cooperatively solve a hands-on measuring and layout problem.
• Recognize how facility design affects fairness in competition.

Equipment for a class of 25

• tape measure: 6
• chalk: 12
• cones: 30
• ropes: 6
• worksheets: 6

Teacher tip

If the schoolyard can't fit those radii, shrink them to between 6 and 9 m. It's easy to set this up as a joint activity with the math department.

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