Mystery Class

scienceteachermamaAnalyzing and Interpreting Data, Asking Questions and Defining Problems, Cause and Effect, Constructing Explanations and Designing Solutions, Crosscutting Concepts, Disciplinary Core Ideas (DCI), Earth and Space Science, Engaging in Argument from Evidence, Expressions and Equations, Measurement and Data, MS-ESS1: Earth's Place in the Universe, Obtaining, Evaluating, and Communicating Information, Patterns, Ratios and Proportional Relationships, Seasonal Change Unit, The Number System, Using Mathematics and Computational ThinkingLeave a Comment




“Mystery Class is a global game of hide-and-seek. Follow photoperiod clues to search for ten secret sites around the world. Track sunlight to solve a mystery—and discover the reasons for seasons along the way.”

Read more about the contest and how to participate here.

Mystery Class is a contest that starts in January and runs until May. I usually start my Seasonal Change Unit in January and finish around March but every Friday until May we devote to solving our Mystery Class location.

I love the fact that I don’t know the locations of the Mystery Classes until my students find out too and I do enjoy solving mysteries! I’ve personally learned so much about all parts of the world and can’t wait until a new Mystery Class starts each year. It also helps my students learn about the seasons and become personally motivated to understand seasonal change because it will help them find their mystery class.


I divide my class into 10 groups and each group is responsible for finding a mystery class. I encourage all groups to help each other as needed but only hold them accountable for their specific mystery class. I create a file folder for each group and that is where all mystery class paperwork is stored from January until May. I keep all file folders in a crate and pass them out and collect them each Friday. What paperwork is stored in the file folders? Here’s the list:

  • Graph and Data Table (This is for 2016. Go here for updated resources) One graph per group but one data table per person (this encourages everyone to participate).
  • World Map with longitude and latitude (world map). One map per group: As we start narrowing our latitude of our mystery classes I ask students to darken the latitudes that they know for sure their mystery class isn’t. For example, by the 2nd-3rd week most student can figure out if they are in the Northern or Southern Hemisphere so they’ll shade in the hemisphere they are not in with their pencil. When we complete our longitude clue calculations (right around the equinox) I ask the groups to highlight that longitude line.
  • A 24 hour clock guide: The 24 hour clock One per group. Students measure time in mystery class using the 24 hour clock. I give them this “crutch” but they only need it for a few weeks. To calculate the photo period I instruct my students to subtract the sunrise from the sunset. There are many other ways to do this, but I do it this way to help my students develop stronger number sense in regard to place value.
  • Mystery Class Clues (data) Collector: One per person. Download here: Mystery Class Clues (I make one 2-sided) Each week students write down one or more clues they analyze from the data. For example if the mystery class has more daylight then our location than they are south of our location (until the equinox). So they would write, “South of 42 degrees north” in the claim column and “because they have more daylight than us” in the evidence part. The reasoning links to our seasonal change unit: “when the northern hemisphere is tilted towards the sun, the more south you go-the more daylight there is” (Now this changes at the equinox, but we start taking data in February). They can narrow it down even further each week by using this resource. This resource lets us see photoperiods from classes all over the world. The closer they get to matching the photoperiod on the same date–the closer they get to their mystery class’ latitude. All the same latitudes have the same photoperiod on the same day. This is something we learn in this series of lessons. I really see the light bulb start to click after these lessons and my students start to make strong connections with our seasonal change unit to finding their mystery class. This is also where they can put their Interdisciplinary Clues as we get to the last few weeks of the contest.
  • Longitude Clues: Right around the March Equinox we get longitude clues. This is perfect for 6th graders because they are focusing on ratios and proportions in Math class and finding our longitude requires proportional reasoning! The Mystery Class program supplies the worksheets (this is the 2016 link). I make one copy per group of the time clues, and one copy per person of the step by step worksheet. We step up #6 as a proportion to solve the problem. Then, I have them highlight the longitude on their maps and they have a pretty good idea of where their mystery class is located. And this is when I bring out the maps! I was lucky that someone donated a bunch of maps of many different countries and several world maps. There’s a thrill in the air as the students open these maps up and start to find the longitude and latitude of their mystery class. I have a huge laminated world political map that I unravel on the floor. It’s so much fun to look around and see these 12 year old students engrossed in maps. Kids just don’t have experiences with actual physical maps anymore. Soon, these maps will be dated or worn down so either I buy new maps or settle for electronic resources.
  • Final Claim and Evidence: The week before I need to enter in my students’ Mystery Class location to the contest, I have students present their final location claim to the class. I usually give students a few days a week before to create a presentation of where they believe their mystery class is located. Their goal is to convince us that they have found their mystery class. I encourage presentations with slides and visuals that show us how they discovered the longitude and latitude and then how the interdisciplinary clues fit their location. The audience’s job is to evaluate their evidence. If the audience feels the evidence isn’t strong enough, they are instructed to kindly give feedback and hopefully encourage the group to re-check their evidence. The groups have until the following week to give me the final paperwork that I submit to the contest. This is the paperwork they give me MysteryClassChart Final claim.
  • Meet Your Mystery Class: When the day finally comes where we get to meet our Mystery Classes, I have students complete this handout. Meet your Mystery Class

Mystery Class bulletin board:

I keep up a class bulletin board throughout the Mystery Class Contest. I put up a giant world map and mark the equator and prime meridian with string. Students use post-its to keep track of weekly where they think their mystery class is located (this also helps me see who may need more guidance). I keep track of all the photoperiods on a giant graph. Any trends we notice from the graph, I write on a sentence strip and post next to the graph. I put an empty desk in front where I keep the bin of file folders that hold the students’ work and folded maps. Here’s a few past pictures of my set up.

bulletin board  bb2

Here are some time zone resources and online map resources I have found useful for this project: 

Time Zone resources

Online Map resources: 

Use these resources to see if the mystery class’ photoperiod matches your students’ ideas: 

If you have other resources that you find helpful please share.




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