Larry is busy working on a broken merry-go-round when Emily unveils a
blueprint of her plans for a beautiful new community center playground.
Emily says that in order to start building the new playground, she would
have to raise at least $4,000.
Donna Leshevski watches as her friend Tommy Smithson rolls to a stop on
his mountain bike, just having gone 2 miles in 7 minutes and 22 seconds.
They discuss how road terrain might affect his time, and Tommy admits that
if he were going uphill, the trip might have taken twice as long. Donna
points out her wheelchair's counter, which counts each revolution of her
wheels. Then, they join Emily Johnson and Larry Peterson working in the
playground of the nearby Edgehill Community Center.
Larry is busy working on a broken merry-go-round when Emily unveils a
blueprint of her plans for a beautiful new community center playground.
Emily says that in order to start building the new playground, she would
have to raise at least $4,000.
Emily, Larry, Donna, and Tommy are headed inside when they find Jasper
hanging a poster outside the community center advertising "The Great
Circle Race." All are intrigued by this mysterious race, and Jasper
explains that the newspaper for which he writes is sponsoring a fundraiser
for a charity: a race with no determined starting point, only an as yet
unnamed finish point. Racers are to find their own starting point at least
5 miles from the finish point, and use any nonmotorized form of
transportation to reach the finish. He explains that the race is open to
people 16 years of age and younger, and the winner receives $5,000 for
their charity.
Donna and Tommy tear off an entry blank and decide to enter the race on
behalf of the Edgehill Community Center. Unfortunately, two bullies, Chuck
Banks and Mark Wilson, warn Donna and Tommy not to bother with entering
the race, because they have a "secret weapon" which will wipe out the
competition.
The next day, Donna and Tommy visit Larry's workshop, where Larry is
beginning work on a 3-D scale model of the race area. Larry explains what
the term "scale" means with his scale model of Charles Lindbergh's
airplane, The Spirit of St. Louis. Then, Larry proclaims that every circle
in the universe holds the property that its circumference is a little more
than 3 times its diameter. He hails this as "The Great Circle Secret." A
skeptical Tommy measures a wheel on the model airplane and Donna's
wheelchair wheel to confirm Larry's proclamation. Larry then reveals the
geometric formula, C=¼d.
Next, Larry helps Donna and Tommy prepare for The Great Circle Race by
sharing with them the story of how he found a favorite fishing spot on a
map by taking cross bearings of two landmarks with a compass.
Three days before the race, Donna and Tommy hold 40-yard time trials in
the community center parking lot to find out what form of transportation
will be the fastest for the race. Donna decides that in order to get a
more accurate idea of what would be best, the racers should time
themselves over a longer one-mile distance, both uphill and downhill.
Someone notices Donna's topographic map and asks her about all the lines.
Donna explains that the lines show elevation above sea level and steepness
of the terrain.
The next day is race day. Jasper announces the four competing teams in the
final heat: Team 1 is Frank Jones on Rollerblade skates; Team 2 is Etsko
Sugita on a 10-speed bike; Team 3 is Chuck Banks and Mark Wilson with a
hot air balloon; and Team 4 is Tommy and Donna with his mountain bike.
Jasper explains that 4 weather balloons have been tethered 2 !s miles due
north, south, east, and west of the finish point for reference. Someone
slashes Tommy's tires. Donna decides that her team may still win with her
in her wheelchair.
Each of the racers attempt to find a valid starting point. Frank takes a
bearing from two balloons and decides he needs to move closer to the
finish point. Etsko takes a bearing and decides that her starting point is
okay. Chuck and Mark cannot see the balloons from where they are, but
Chuck claims to know their location and tells the drivers to take him 6
miles south, "in the direction of the red arrow" on his compass. Tommy
takes a reading with Donna, and they decide that they have a valid
starting point.
Jasper and Larry keep track of how long it takes each team to travel each
of their first 3 miles and posts it on a board. Jasper announces: "Team
Number One did the first three miles in 18 minutes. Team Number Two did
three miles in 17 minutes. Team Number Three, Chuck and Mark in the hot
air balloon, they don't have an exact number, but they're going like the
wind. Team Number Four did the first three miles in 20 minutes."