We completed the first two weeks of data recording. From the beginning until the spring equinox, all you need to do is record sunrise and sunset data, calculate the photoperiod (amount of daylight), and graph the data. Photoperiod reveals the latitude of the mystery classes since it is different for every latitude yet constant along that latitude around the globe. This gives you several weeks to explore related concepts.
Week 1 we investigated globes, maps, and the longitude and latitude lines on them. This information is readily available in most atlases. The National Geographic Xpeditions site has a lot of great information and related activities. I printed a copy of the world map for each student and gave them coordinates to mark to show how longitude and latitude gives you a global location. I assigned the program Globes and Their Uses on Discovery Streaming. We also learned about dividing a circle into 360 degrees as part of this lesson. We used the diagrams from the program to illustrate.
Week 2 we investigated the Reasons for the Seasons, watching the video of the same name on Discovery Streaming, and reading the Let's Read and Find Out book. There's a nice interactive on Teacher's Domain, too. They figured out why classes 3 and 8 (both of which Ds#2 has) have photoperiods of 0 and 24 respectively and near the equator is 12 hours. From that they learned that photoperiod indicated latitude, that north of the equator the photoperiod was increasing, and south of the equator it was decreasing. I even caught two math errors in photoperiod because the trend didn't fit that pattern. And now that we have a line drawn on our graph, the overall pattern makes sense to them.