This is an excellent intermediate (grade 5-8) routine! This will take at least 2-4 math periods to complete at a time. It involves developing and practicing number sense across whole numbers, fractions and percents. Devices are handy (especially for accessing and recording information), but not totally necessary. It can all be done on paper, too. Have base ten materials ready for representing and building numbers, if you can. The kids will need to read, write, hypothesize, discuss, offer and listen to opinions, make connections and hopefully be blown away.

**Step 1: The Experts**

An expert’s job is to read ahead and absorb information about the chosen mystery numbers topic. They will help their classmates uncover the mystery by being there to take questions. Experts can also create power points or some sort of presentation for the big reveal (Sample: Basketball Points)

The first time around, this should be your job. You are modelling it for your future student experts. By the way, I will post up the necessary links!

**Step 2: Introducing the Mystery Numbers**

Show students the raw numbers randomized in a list. Their first job is to simply organize and break these number down a little. They should be able to read them, build or visualize them, expand them, explain place values and place them in some sort of order. They can do this on paper or on their devices. Handy tip: after students have built the numbers, they should take a photo with their devices and link it to their work.

**Step 3: Game Time**

Once the kids feel comfortable with the numbers, they’ll need to determine the topic. This is where your experts come in. Play a little 20 questions as a class. The experts can only answer yes or no to these questions. Keep going until the topic is uncovered! They range from light and fun to really serious.

**Step 4: Story Details**

Now that the topic is uncovered, the kids need to revisit the numbers. Any thoughts on what these numbers are describing? Write down hypothesis/guesses. Compare these through discussions (whole class, small group, partners or a bit of everything!). You may want to generate a list of units that make sense. Dollars? Grams? Might some numbers actually represent percentages? At this point, you can reveal the list with the units attached. Does this make the story clearer? Time to give the kids a second chance to revise their thinking. They should do some research during this phase, too.

**Final Step: The Big Reveal**

Time to compare results! Once the real list is revealed and kids have had a chance to see how close they came, they can dig into the story a little further. For example, once the kids know the GDP of various nations, they should be introduced to wealth sharing percentages. It creates a fuller, more complex picture. They should have a chance to ask and wrap their heads around possible answers. Why are there two completely different lists for the top 10 box office earning movies of all time? Why are civilian casualty numbers for World War 2 rounded to the nearest thousand? How did they determine world populations ten thousand years ago? They say that numbers don’t lie, but how can we trust them for sure?

These are all interesting and important questions. Stoke your students’ enthusiasm the best you can during this phase. Pay close attention to conversations, mining them for insights and questions. Be curious yourself. This is my favourite part and will be your’s too.

Stay tuned for the next posts…I’ll be laying out topics and number lists next.