The Tennis Courts, while next to an elementary school, are not a part of school property. They are actually an city park. But to find the cache, you'll need to dust off your math skills. This should be a good first mystery cache for kids, they should be able to do the counting and addition, but may need some help with algebra :). Container has room for a few small goodies.
a = There is a water fountain here, this is the number of drain holes in the water fountain.
b = The number of steps you need to take to get up the nearby stairs onto the road (don't count the steps, count the number of times you take a step up)
c = Number of tennis courts.
d = Number of doors to get into the fenced in tennis area.
e = The number of signs hanging on the tall fence surrounding the tennis courts.
Once you have the numbers you can plug them in here:
47°38.(d * 2)(d + c)(a) N
122°10.(b * 2)(c + e) W
You can check your answers for this puzzle on GeoChecker.com.