Posted by: jwhiff | August 4, 2018

MN11: Rick Hansen (Canadian Hero 2)

I didn’t think of tackling a Rick Hansen Mystery Numbers last year! I wish I had. It is an excellent follow up to Terry Fox.

New to Mystery Numbers? Click each heading for more information.

The Numbers:




40,075.16 (round to the nearest one, if you wish)











Flat tires






(One of these units needs to be used twice)

Expert Source: click here

Just like with Terry Fox, I would get the kids to read, find out which units match which numbers and write down a little extra information to make the list more meaningful.


Posted by: jwhiff | August 1, 2018

MN10: Terry Fox (Canadian Hero 1)

I did this with my grade 3/4 class at the beginning of last school year.  It worked really well for that age group and will work well for grade 5’s too.

New to Mystery Numbers? Click the main headings for information.

The Numbers:  By the way, I added a prep step.  I didn’t simply provide my students with a list of numbers.  I typed them up, printed and cut them out.  This helped several of my students needing adaptations.  It made it much easier for sorting.

















starting date

* some units need to be used more than once!

Expert Source:  By the way, I gave all students access to this link because I had a reading and research objective as well.  My squirrelly class was very intensely focused for this step.  They were to find and record extra information to give each unit even more meaning.  For example, it is useful to know that 42 goes with km, but it becomes even more meaningful when you know that Terry Fox ran 42 km EVERY DAY!


Posted by: jwhiff | July 30, 2018

MN9: The Top Ten Highest Grossing Movies (List 2)

This one is completely different than the first one!  There are two main reasons for this: one is ticket price inflation, the other is worldwide vs domestic numbers. See if your student can figure these out. By the way, I regularly test these lists out on my sons (aged 12 and 14) just to see if they enjoy solving them.  They were particularly interested in these last two lists 🙂

Not sure how Mystery Numbers works? Click the main headings for information.

The Numbers:











Unit: Dollars.  Like with MN8, I recommend that you get your students to express these numbers using the unit billion dollars and rounding to the nearest thousandth.  Why? They’ll often see large numbers expressed this way because they are easier to read. Plus, it is always a good idea to remind them that even a thousandth of a billion dollars is still a lot of money!

Movie List:

Dr. Zhivago

Pirates of the Caribbean

Gone with the Wind

Wizard of Oz



The Exorcist

Indiana Jones

E.T.: The Extra Terrestrial

Snow White

Star Wars: A New Hope


The Sound of Music

Expert Source:

Business Insider: Highest Grossing Films of All Time (Click Here)


So! A lighter topic. Still interesting, though. I recommend tackling MN9 right after this. Two completely different highest grossing movies of all time lists? Why?

Not sure how Mystery Numbers works? Click the main headings for information.

The Numbers:











Dollars! Get the kids to switch it to billion dollars to get them practicing expressing the numbers more simply. Round to the nearest thousandth. For example: 1,519,557,910 dollars becomes 1.520 billion dollars.

Movie List:

Marvel’s The Avengers

Black Panther



Avengers: Infinity War

The Lord of the Rings: The Return of theKing

Harry Potter and the Deathly Hallows Part 2



Furious 7

Avengers: Age of Ultron

Star Wars: The Force Awakens

Jurassic World

Expert Source:

Newsday Biggest Box Office Hits of All Time: click here

Posted by: jwhiff | July 25, 2018

MN7: Lower GDP per Capita: Is it a problem?

Take a little time to explore GDP per capita.  If it is low, is it really a problem?  How can you tell?

First, GDP per capita is an imaginary measure.  It is a basic average calculation of GDP divided by the population of a given nation.  In reality, no wealth is ever distributed that way.  There are always those who earn more than others.

Here is an activity you can try with your class. It works best if you have a neighbouring class that is willing to work with you.  One class will have a high GDP per capita and the other will have a lower one.

Your students are all members of a tiny, imaginary island nation (you can come up with a name if you wish). This island is located near another island nation.  The islands are very different from one another.

Population of the island = population of your class

Cut the following cards out (when you click one of these links, you will not automatically see the document. Click the link a second time and the document will appear): GDP per capita Island 1    GDP per capita Island 2

Distribute them so that each member of your class has one.  On each card is basic personal information and annual income.


Use income information to calculate the GDP and the GDP per capita for your nation.  You can give partners a class list and have them move around to collect the necessary information.  Regroup and double check  answers as a class.  You can also take your time with this information to practice or review median, mean and mode.

Compare the information.  Which nation is the wealthiest? Even though GDP per capita hides inequality, does it still give you a good measure of which country is wealthier?  Why do you think one country is so much wealthier than the other? Is it a problem that one nation has much less than the other?

Time to look at two other good stats: Life Expectancy and Literacy Rates

Each card has two other pieces of information: whether or not you can read or write and how old you are when you die.  The class is going to use this information to calculate Life Expectancy averages and Literacy Rates (%).  Calculate the overall rates for your class and also look at the difference between male and female results.

Compare the information. Which nation has the longest average life expectancy? Which nation has the highest literacy rate? Are there any differences between male and female rates for your nation?  What does this all tell you about quality of life in your island nation? Does this change if you are a female? Why do you think the two nations are so different? Where would you rather live? Why?


Check out the GDP per capita, life expectancy and literacy rates for the 10 underprivileged nations: MN6. Are these nations plagued with low life expectancy and literacy rates, too?  Would they be difficult places to live?

Plus, of course, it is important to reflect on GDP per capita as an accurate measure of poverty.  Why is it always important to look at other statistics (like literacy rates and life expectancy) before using it to judge a country? You can look at wealth distribution as well, if you are on a roll.  There is a tidy little measure called the Gini Index on the CIA World Factbook that you can explore.  This might be a good time to compare to Canada, as well.  What is our GDP per capita?  Is our wealth shared equally?

Posted by: jwhiff | July 25, 2018

Uncovering the Story Behind Each Number List

Each number list is paired with a corresponding list that provides it with context and meaning.  There are lists of people, countries, animals and objects, for example. Once the kids know the basic topic, numbers and unit, they need to properly match the corresponding lists.

You have a choice to either provide the kids with the randomized list directly after the unit has been revealed or make them play for it a little longer.

If you choose the second option, you need to get them to create a preliminary list on their own.  For example, if the kids know that the numbers represent highest country populations, they then work together to generate lists of possible countries first.  I like to provide my students with maps that they can interpret here.  Great for the geography skills.  Be careful not to let them on their devices, however!  Too easy to cheat :).  I would print one out, use an atlas or project one on the board.

If you choose the first option, know that I always include a couple of extra bogus items on each list.  They should eliminate these first.  Again, play for points.  Then, they need to match up each item with a number. They should work in groups of course and sometimes they will still need help in the form of a map or a bit of extra information.

Time to compare results!  How close did they come?  It would be great if your expert created a flashy powerpoint for this stage.  Assign positive points for every correct match and negative points for every mistake.

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.

Posted by: jwhiff | July 25, 2018

The Numbers!

Show students the raw numbers randomized in a list. Their first job is to simply organize and break these numbers down a little.

Here are some tasks to build number sense:

  • Order them.
  • Provide word forms.
  • Expand them.
  • Explain the place value of each digit.
  • Represent them using blocks, base 10 material or paper.

I wouldn’t necessarily get your students to do all of these tasks all of the time.  Some of them are necessary (ordering, word forms), but others can be used as you see fit.

Handy tip: after students have built the numbers, they should take a photo with their devices and link it to their work.

Game Time!

Once the kids feel comfortable with the numbers, they’ll need to determine the topic. This is where your experts come in. If you like, 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!

You can play teachers vs kids for points.  If they hit 20 questions without guessing the topic, the teacher takes a point for every question over 20.  Kids get points for the number of questions left until they reach 20 questions.  I would introduce integers this way.  Everyone starts at zero.  Kids points have a positive value, teacher points have a negative value.  Track points using two different number lines.  Kids know how many point they have by adding the negative points to the positive points.  Anyway, a little friendly competition is always fun!  Keep track of the points over time. You determine the prize (I like a fun game outside).

Story Details!

Once the topic is uncovered, the kids need to revisit the numbers. Any thoughts on what these numbers are describing? The kids can brainstorm in groups.  Compare ideas in a class discussion.  Dollars? Grams? Might some numbers actually represent percentages? What makes the most sense? Again, you can play for team points.  The class can decide how certain they are about their answer.  Very certain? They can risk a larger number of team points.  Not as certain?  Risk fewer.  If they are wrong, the teacher collects what the class risked.  Get your expert to reveal the unit!

Posted by: jwhiff | July 24, 2018

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!

Posted by: jwhiff | July 24, 2018

MN6: GDP of Underprivileged Nations

Now that your class has examined the earnings of the wealthiest people in the world, time to look at 10 nations that are nowhere near as wealthy as those 9 people. Remember to click on each heading if you need an explanation of the process.

Here are the GDPs of 10 Mystery Nations:











Unit: Billion dollars. Thought I would do the reverse this time. What would the numbers look like if they were expressed in dollars instead of billions of dollars?

Experts: Your expert can find the correct matches by searching in this GDP list from the CIA World Factbook.  It is going to take a little searching, so you want a patient expert this time.  Plus, your expert may get confused about the 0.0015 number.  It is expressed as 1.5 million dollars in the original list.  I just converted it to billion dollars to make it more challenging and consistent with the other items.

By the way, you might want to supply all of the students with the following links this time.  They won’t know much about these places to begin with and so will resort to blind guessing.  You could also project this map to help them with the task.  These websites will help them to narrow the list down at least.





South Sudan





Democratic Republic of Congo (DRC)


Central African Republic



I chose these nations not because they have the lowest GDPs, but because they have the lowest GDP per capita rates. This means that if the GDP of these nations were split evenly (and they aren’t, of course), their citizens would have the lowest individual wealth in the entire world.

As it is, it is pretty shocking to see the wealth of the ten nations in comparison to the wealth of the top nine billionaires (MN5). It is claimed that the wealth of these individuals is not only greater than the combined GDP of these nations, but of the combined “wealth” of more than half the world’s population! Is this true? I recommend investigating this one. What is the total wealth of these billionaires? How many countries’ GDPs equal their wealth? What are the populations of these countries? Here a couple of handy CIA World Factbook links to help you out:



Posted by: jwhiff | July 23, 2018

MN5: Richest People

This is the start of a very interesting story. I highly recommend NOT doing this lesson as a stand alone. Follow it up with MN6: GDP of Underprivileged Nations. It paints a very stark picture of wealth inequality. Remember that if you would like to understand the Mystery Numbers process better, please click on the headings.

Here is the list:










Unit? Dollars. In the article, the unit is billion dollars. This is, of course, much easier to read. Recognizing the value of the 8 in 3.8 billion dollars, for example, is a very important numeracy skill that I would practice here. Change the unit and get the kids to practice recording the number. What if the unit were million dollars? Thousand dollars?

Expert source: Independent Article (Richest People)

This article was written in January 2018, so it is relatively current. Individual wealth fluctuates very quickly, so it won’t be perfect, for sure. It’s an accessible article for middle school kids, however. Another article that is quite accessible and provides good good biographical info for your expert is from Time Magazine: Richest People. I didn’t go with this article because the numbers are more highly rounded. The differences between the articles make for an interesting discussion, though.

Richest People: Who earned what?

Jeff Bezos (founder of Amazon)

Carlos Slim Helu and Family (controls Latin America’s largest mobile telecom firm-America Movil.

Mark Zuckerberg (founder and CEO of Facebook)

Tim Sweeney (founder of Epic Games and creator of Fortnite)

Warren Buffett (successful investor and owner of over 60 companies, including Dairy Queen and Duracell batteries)

Larry Ellison (co-founder of database company, Oracle)

Bernard Arnault (owner over 70 exclusive brands including Louis Vuitton, Sephora and Dom Perignon)

Queen Elizabeth (British monarch and owner of property, rare items and investments)

Bill Gates (co-founded Microsoft)

Larry Paige (founder and CEO of Google)

Amancio Ortega (co-founded Inditex, parent company of fashion retailers such as Zara)

Remember that not all of these people are the real deal. It bugs me a bit the Independent article doesn’t include the Koch brothers, because they are on a bunch of other lists. I figure this could be a part of the discussion as well.

Ethical concerns about amassing such wealth? This will make for an interesting debate, especially when you move on to the GDP of Underprivileged Nations.

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