Esti-Mysteries: Estimation Meets Math Mysteries

EM Clue 2

Introducing Esti-Mysteries!  Each image invites students to wonder what number is represented by the image.  As you click through the each Esti-Mystery, clues will appear that will allow the students to use math concepts to narrow the set of possibilities to a small set of numbers.  In the end, the students will need to call upon their estimation skills to solve the mystery and find the missing number.

NOTE:  In addition, to these original Esti-Mysteries, you may also want to visit the brand new post 51 Esti-Mysteries.

Here is an example:

ESTI MYSTERIES IMAGE

EM Clue 1

EM Clue 2

EM Clue 3

Download the Esti-Mysteries, try them in your class, and let me know about your experience.

 

Update:  Here are 4 Printable Esti-Mystery Charts you may enjoy using with Esti-Mysteries.

Update:  Here is the Full Set of Esti-Mystery Clues (without images) to allow you to browse through the Esti-Mystery Concepts.

 

As always, you can find me on Twitter @stevewyborney

 

After reading this blog post, take a look at  THE 12 MOST POPULAR MATH STRATEGIES AND DOWNLOADS ON THIS BLOG.

 

 

Esti-Mystery #1 The First Mystery

EM 1 showing 2 clues

 

Esti-Mystery #2
EM 2 showing 2 clues


Esti-Mystery #3
EM 3 showing 2 clues

 

Esti-Mystery #4

***This is the one where the numbers on the dice are first used as a clue.
EM 4 showing 2 clues

 

Esti-Mystery #5
EM 5 showing 2 clues

 

  Esti-Mystery #6

***The most challenging one yet!
EM 6 showing 2 clues

 

Esti-Mystery #7 “The Dice Jam”
EM 7 showing 2 clues

 

Esti-Mystery #8 “Bright Beads”
EM 8 showing 2 clues

 

Esti-Mystery #9  “Cupside Down”
***This one that may lead to the greatest debate and surprise at the end.
EM 09 Showing 2 Clues

 

Esti-Mysteries #10  “Yellow Yarn”
EM 10 Yellow Yarn Showing 2 Clues

The Smaller Number Series

This next Esti-Mysteries was requested for a kindergarten class.  Enjoy!

Esti-Mystery:  The Smaller Numbers Request

***This is a great one to use with kindergarten students.
EM pic The Smaller Numbers Request

 

Esti-Mystery:  “Sinker?” (from The Smaller Numbers Series)
EM 00 Sinker Showing 2 Clues

Other Posts and Resources Which May Be of Interest

51 Esti-Mysteries – 51 (fifty-one!) brand new Esti-Mysteries which I’ve already started posting here.

Splat!  (50 downloadable, animated lessons)

The Fraction Splat! Series (with 20 more downloadable lessons)

Splat! for Google Slides (This is the one you want if you don’t have PowerPoint but do have Google Slides.)

Cube Conversations  (80 downloadable, animated lessons)

Tiled Area Questions

Thank you for visiting my blog!

All my best,

Steve

P.S.  Please feel free to post your reflections in the comments below.

99 Comments

  1. kheloufi on July 6, 2023 at 6:26 am

    I loved this content. Thanks for creating it.

  2. kheloufi on July 2, 2023 at 6:25 am

    Looks like a fun place to visit and stay.

  3. tassnime on April 17, 2021 at 2:24 pm

    Amazing tips. Thanks a lot

    • Steve Wyborney on May 2, 2021 at 8:26 am

      My pleasure!

  4. amel fs on February 28, 2021 at 4:56 am

    Thanks for posting this information ,,it was very useful to me

  5. Amy on January 12, 2021 at 4:27 pm

    Hi Steve!

    My students absolutely love completing your Esti-Mystery and Splat problems! Thank you so much for creating them!

    I’ve had a few students ask if it was possible for you to create a short video or time lapse video at the end after the reveal to show the quantity spread out on a table.

    Thanks again!

  6. Harminder Kaur on November 9, 2020 at 3:24 pm

    Hi Steve!
    We did our first esti-mystery today, and the students loved it! However, when I tried to click on the red button to reveal the answer, it didn’t work! Please help! The students really want the answer.
    Thanks!

    • Steve Wyborney on November 15, 2020 at 12:05 pm

      Thank you for asking this question. To show how to do this, can you download one of the most recent Esti-Mysteries from my latest blog post? I’ll place the link below. On the newest ones, I’ve added some notes that will answer your question about the one you are working on. You’ll see that to make the reveal work the PowerPoint needs to be playing (Slide Show / View Current Slide) or if using Google Slides to click on Present. The reason that makes it work is that it activates the animation that allows the reveal to work. If you download an Esti-Mystery here, you’ll see what I mean: https://stevewyborney.com/2020/11/new-esti-mysteries-and-number-sense-resources-every-day-for-the-rest-of-the-school-year/

      • Michelle Rogers on November 15, 2020 at 3:43 pm

        I’m not sure why it works this way on my computer, but I discovered (stumbled across) that I have to open a new Google Slide document and import your mystery file into the new presentation for them to work for me. My students love them!!! Thank you so much!!!

        • Steve Wyborney on November 16, 2020 at 7:06 pm

          Michelle, I’m glad you have found this way to make it work. I hope you enjoy the upcoming materials!

  7. Michelle Rogers on November 4, 2020 at 3:56 pm

    I love these mysteries! I can’t seem to make them work on my MacBook, though. When I open them it just shows the screen, but I can’t click to reveal things. What am I doing wrong? I used someone’s YouTube video from spring closures using one of the mysteries to show my students. They loved it so much I want to show many more!

  8. Erin Chawla on October 30, 2020 at 10:28 am

    Hi Steve,

    Thank you so much for sharing these Esti-Mysteries with the teaching world. I teach a Grade 5 and 6 class and we are really enjoying them! My students often disagree with the answer when revealed – not that they disagree that it follows all rules outlined in the clues, rather they argue that the final number does not match the picture. I told the kids they need to work on their powers of estimation.

    So, our question is, do you create the photos with actual items and verify the amount, or do you find photos and make a logical guess about how many are represented? Help me teach these kids a lesson!

    Thanks again for being awesome.

    • Steve Wyborney on November 1, 2020 at 9:20 pm

      Hi Erin,

      What a wonderful question. I create each and every image from scratch. My rule is to triple count everything so I have the exact number which I keep a secret until the reveal is clicked. One of the key parts of creating an Esti-Mystery is to make sure there are 2-3 plausible remaining answers at the very end that haven’t been eliminated by the clues, otherwise there would be no need to estimate and there would be no sense of mystery remaining. So, after the final clue, there is one final rich conversation about what the answer might be – and there is a final rich estimation experience and conversation. When students (and adults) estimates are off they are often too low rather than too high. I hope that helps provide some useful information. Your students might really enjoying creating their own Esti-Mysteries and sharing them with each other. I hope you have a great week!

  9. Heather on August 14, 2020 at 1:58 pm

    Hi Steve,
    I was introduced to your site during a course I took on data science recently. It is amazing. I am so excited to use it in the class. Thank you for all your hard work.

    • Steve Wyborney on August 20, 2020 at 6:53 am

      Hi, Heather. Thank you for taking time to comment. It’s great to hear that the site is being shared during a course!

  10. Jordan on May 29, 2020 at 4:07 pm

    These are great! Thanks Steve!

    • Steve Wyborney on May 31, 2020 at 8:31 am

      Thank you so much!

  11. Jolie on January 9, 2020 at 6:46 pm

    I teach students in grades 1st – 5th grade for gifted. They love your Esti-Mysteries and I enjoy the challenge that it brings. I have used them primarily for 1st – 3rd grade students. Thanks so much for making these available. Keep it up!!!

  12. Stephen Geurts on January 2, 2020 at 5:19 pm

    I’ve begun using esti-mysteries in my classroom and they’re a hit! Thank you for them.

    Is there a way to have them work with google slides? I downloaded them onto ppt and they worked perfectly. I tried with my chromebook and they didn’t work.

    Thanks!

  13. Jennifer Cataldo on November 6, 2019 at 10:39 am

    Hi Steve,
    My kids are so excited by yours, they have written their own Esti Mysteries! Do you have a template we could use on PowerPoint so they could plug in their picture and clues?
    Thanks so much!
    Jennifer Cataldo
    Math Interventionist

    • Steve Wyborney on November 18, 2019 at 6:13 am

      Hi, Jennifer. I have an entire class for purchase on how to create Esti-Mysteries. For this purpose, you may simply want to use one of the existing esti-mysteries as a template.

  14. Savanna Moore on October 30, 2019 at 11:40 am

    Hello,
    On Esti-mystery #4 clue number 4 says the sum of numbers that can be seen is not a digit in the answer. So if we add 1+3 as 4, so how is the answer 47?

    • Steve Wyborney on November 2, 2019 at 9:21 am

      Great question. On that Esti-Mystery there is also a 5 in view on the top of the die. Since the faces representing 1, 3, and 5 call all be seen the wording of the clue will eliminate numbers with the digit 9 but numbers with the digit 4 will still be possible. Thanks for reaching out with this question.

  15. Jeff Kurtz on October 24, 2019 at 5:18 pm

    We just discovered your wonderful Esti-Mysteries. My teaching partner (next door) and I know when the other is doing one of them because we can hear the roar of joy and satisfaction through the wall when the final answer is revealed.

    Thanks so much for creating those.
    Regards,
    JK

    • Steve Wyborney on October 25, 2019 at 6:39 am

      Hi, Jeff. Thanks for sharing this with me. I do love that moment of the reveal! I’ll keep writing and posting more of them.

  16. Jess Fagan on October 23, 2019 at 4:13 pm

    Hi Steve!

    I love these resources and use them often! I do have a question about Esti-Mystery 4. Could the solution also be 67? Or is that unreasonable due to the size of the vase? I have a very curious 7 year old wondering and I’d love to give him an answer because we concluded 47 was the answer, but then realized it possibly could be 67 too. Thanks so much for your time & creating math resources that make school more fun and engaging!!

    • Steve Wyborney on October 24, 2019 at 6:42 am

      Great question, Jess. Whenever I write Esti-Mysteries, the clues always narrow it down to a small set of numbers – often 2 or 3 numbers – and the number of actual objects is one of those numbers. For Esti-Mystery 4, both 47 and 67 work with the clues, so they are part of the final discussion. However, the actual number of objects in the container is 47. I hope that helps!

  17. Jordan on October 16, 2019 at 3:48 pm

    Hey Steve,

    We did one of your Esti-mysteries as a staff at a PD this past week – it was awesome! I wanted to do a few with my 5/6 class but haven’t been able to properly download them with a “reveal” that works to show the final answer. Is there a step I’m missing or a trick to this?

    Thanks!

    • Steve Wyborney on October 29, 2019 at 4:40 pm

      Hi, Jordan. I’m catching up on comments today. I think I have the solution for you. Can you download one of the latest Esti-Mysteries, one that says “Brand New” next to it? Here is the link to 51 Esti-Mysteries.
      As I make the new ones, I built in a feature that will make this work – or will show you what to do to make sure it works. Try one of the new ones out and let me know if the yellow boxes on it answer the questions here. I appreciate the note.

  18. Scott Slonim on October 14, 2019 at 9:41 am

    We have started sharing our student created mysteries on HTV, our live news show! Here is day one:

    https://www.youtube.com/watch?v=oykv5vwE2qY

    It starts at 2 minutes and 36 seconds!

    • Steve Wyborney on October 29, 2019 at 4:45 pm

      What an amazing production!

  19. Scott Slonim on October 10, 2019 at 9:57 am

    Hi Steve,

    We have a live daily news show that we stream on the internet to our school and the world. We are going to start having students make them and then show them on our show each week. One clue a day starting on Monday with the final answer being given on Friday!

    • Steve Wyborney on October 29, 2019 at 4:48 pm

      I just caught up with the video you posted. How amazing! How is it going?

  20. Dawn on September 17, 2019 at 12:18 pm

    Hi there! A friend told me about this site. It looks great. How do I access each mystery for the kids to see on the smartboard AND the answers?

    • Steve Wyborney on September 24, 2019 at 9:04 pm

      Yes, you can download each one and the answers are found under The Reveal. Be sure the slide show is in presentation mode so that the reveal will show the answer.

  21. DORIA V HABIB on September 10, 2019 at 1:01 pm

    Hi Steve, I just started doing the esti-estimations. My kids love them. Is there away to subscribe and have access to more? Thanks!

    • Steve Wyborney on September 13, 2019 at 6:19 am

      Yes, you can use the subscribe box is on the left side part way down the page. If you click here, and scroll down a little, you’ll find it.

  22. djamila_st on September 9, 2019 at 2:38 pm

    Thank you for this timely article.

  23. Amelia Carter on September 9, 2019 at 12:29 pm

    Steve,
    Thank you for these! My 3rd and 4th graders are creating their own Esti-Mysteries today using a variety of objects, jars and notecards for clues. We’ve invited other classrooms to come and solve them tomorrow. So much fun!

    • Steve Wyborney on September 13, 2019 at 6:17 am

      Hi, Amelia. This is so great to hear! This is such a great approach to share their creations with other classrooms. Nice work! Have a great day!

  24. helene on June 1, 2019 at 4:43 am

    well done thank you

  25. April Pillsbury-Lloyd on March 13, 2019 at 6:19 am

    I’ve used estimation clipboard and the esti-mysteries with my multi-grade classroom (2nd-8th). My kids love the esti-mysteries, so we made our own. Any ideas where we could set up a repository of student created challenges?

  26. Maria on February 17, 2019 at 2:00 am

    Steve,
    Hello from Hong Kong! Thank you for the esti-mysteries, so much fun! I introduce it at the beginning of the week, then I leave a print out on the board with all the clues so everyone has a chance to think about it, then we have a reveal later in the week. Oh, the suspense! I will also use them at our ‘family fun Math night’ later this week – I’ll make sure I give you cred 🙂
    I saw in a previous post that a teacher will have the kids create some – that’s a great idea, I am planning on having the G4s create them for my G3s.
    Thank you for sharing – love your blog!
    Maria

    • stevewyborney@gmail.com on February 20, 2019 at 8:18 pm

      Thanks, Maria. I’m so happy to hear that these are being used in Hong Kong! Having the students create the Esti-Mysteries is a very rich and rewarding experience. Thank you for the kind words and for taking time to leave a comment.

  27. John and Maya on January 27, 2019 at 9:10 am

    Thanks Steve,
    my daughter enjoys your esti mysteries. She wrote one for you with a unique solution.

    Jar of sweets
    Clue 1: It is a 2 digit number
    Clue 2: Both digits are odd
    Clue 3: It is not a prime number
    Clue 4: If you add the digits you get 6
    Clue 5: The last digit is smaller than the first.

    • stevewyborney@gmail.com on February 20, 2019 at 8:34 pm

      I am so honored. I have worked through all the clues, considered the possibilities, and I believe the answer might be 51. I would love to hear if this is correct. That was very fun!

  28. Michelle on January 24, 2019 at 12:51 pm

    Hi Steve, My students are loving the Esti-Mysteries! It’s like a party at the beginning of class. Today we completed Esti-Mystery #10, “Yellow Yarn”. One of my students said, “I think I have this guy figured out. He left us a clue! The number skipped was 12 and we were counting by 6, so my first estimation was 72.” HMMMMM, coincidence or truth?????

    • stevewyborney@gmail.com on February 20, 2019 at 8:37 pm

      I remember considering making that a clue, but thought it jumped too quickly to the answer. I did wonder if anyone would notice that, and now I know! Great catch! I a impressed!

  29. Mark Martin on January 16, 2019 at 9:52 am

    I used them with my 7th grade Math Connections class, they loved them! I then tried them with my Honors Math 7/8 class…they loved them too! Great way to connect with all levels of students in a fun way! Thanks Steve.

    • stevewyborney@gmail.com on January 18, 2019 at 6:41 am

      Hi, Mark. This is great to hear. I really aim to share materials that can be used across a range of levels, and I’m glad to hear how much your students are embracing them. I’ll be posting more that I think your students will really like – and that will launch some powerful math discourse.

  30. AJ Wall on December 19, 2018 at 11:43 am

    This is awesome! Is there a way to share it with me through google drive or email? I’m not sure how to download it.

    Thanks so much!

    • stevewyborney@gmail.com on December 21, 2018 at 6:47 am

      Hi, AJ. To download it, click the blue link above each picture. Then click the blue link on the download page and then it should download right to your computer. Let me know if you have any trouble with that process. Thanks for commenting.

      • AJ Wall on December 21, 2018 at 10:07 am

        Thanks so much! I didn’t see that before. I’ve them now – can’t wait to try them!

      • Sara Ostrander on January 29, 2019 at 7:53 am

        Hello…I really want to try one of these with my students but cannot get the reveal to cooperate. I may try it anyway but seems like it would be better with a reveal. Any suggestions?
        Thank you.

        • stevewyborney@gmail.com on February 20, 2019 at 8:28 pm

          Great question. 9 times out of 10 the solution lies in going back and making sure that the show is playing. You can use most of the slides just by clicking through, but the reveal slide in particular requires that the show is playing to work.

    • cp on January 17, 2019 at 1:02 pm

      These are so great. My students love them. Will you be making more that are directed towards the younger years?

      • stevewyborney@gmail.com on January 18, 2019 at 6:40 am

        Yes, I have more for the younger years. I’m looking forward to posting them.

  31. Sharon Enea on December 19, 2018 at 9:57 am

    This is great! I tried my first EstiMystery today with my small groups! It was a big hit! The math conversations were amazing and lead to increased student number sense! Thank you so much!

    • stevewyborney@gmail.com on December 21, 2018 at 6:49 am

      Hi, Sharon. It’s great to hear this! Thank you for letting me know. There are more to come soon!

  32. Kris Weir on December 17, 2018 at 3:06 pm

    My 4th graders have loved these and ask daily if new Esti-Mysteries are available. They have even started making their own for their buddy class and the Kindergarten classes at our school. Thanks for inspiring them!

  33. Linda Colletti on December 12, 2018 at 9:31 pm

    Hi Steve,
    I would love it if you would make more smaller numbers Esti-Mysteries. I teach Kindergarten and these would be so good for them.
    Thanks.

    • stevewyborney@gmail.com on December 13, 2018 at 8:57 pm

      Hi Linda,
      I have several more that I’ll share soon. It sounds like I should bump one of the kindergarten versions to the top of the list. Hopefully you’ll see one soon!

      • Linda Colletti on December 13, 2018 at 10:03 pm

        Excellent, thanks so much!

        • stevewyborney@gmail.com on December 22, 2018 at 8:55 am

          My pleasure, Linda! Thank you for leaving a comment!

      • Morgan on December 18, 2018 at 10:49 am

        I did the eraser one with my 1st graders and they loved it! I would love some more of these designed for younger grades.

        • stevewyborney@gmail.com on December 21, 2018 at 6:55 am

          Thanks, Morgan. I’ll be making more soon.

  34. K on December 12, 2018 at 8:57 pm

    Hi Steve, Thank you so much for all of the time and effort that you put into creating these presentations. My fourth graders love them! We use them nearly every day for our morning warm-ups or number talks. The are the fuel for some wonderful math conversations and I think it is wonderful that you keep them free. Thank you for being so generous and for supporting busy teachers with such high quality resources.

    • stevewyborney@gmail.com on December 13, 2018 at 8:58 pm

      My pleasure! I’m really glad to hear how much your students love them and also how they are having such rich conversations!

  35. Linda Colletti on December 12, 2018 at 8:53 pm

    Hi Steve,
    I would love it if you would do more smaller numbers Esti-Mysteries. I teach Kindergarten and these would be so good or them.
    Thanks.

  36. Patti Kleinhanzl on December 11, 2018 at 10:21 am

    I did this with a group of third graders. They cheered so loudly when they got the answer correct, that the teacher next door had to come and see what we are doing. I’m now going to do the lesson with her class tomorrow!

    • stevewyborney@gmail.com on December 13, 2018 at 9:00 pm

      I love it! What a great way to spread the enthusiasm! If I heard cheering in the next classroom I would go find out what was going on, too.
      Thanks for sharing!

  37. iuliia on December 11, 2018 at 9:54 am

    Great slides, but the red “reveal” box does not disappear… not sure if that is how it should work…

    • stevewyborney@gmail.com on December 13, 2018 at 9:01 pm

      If you play the PowerPoint, it should disappear at the end. However, if it doesn’t a simple trick is (when it’s not playing) to simple drag the box off of the number that is below it.

  38. Jaime on November 30, 2018 at 6:58 am

    Help! I can’t get the answer to reveal for esti-mystery 6! Am I doing something wrong?

    • stevewyborney@gmail.com on December 6, 2018 at 6:40 am

      Hi Jamie,

      I just caught this comment and will put the answer at the end in case you can’t find it there. The answer is to be sure the PPT is playing so that it will make the red reveal box disappear. A 2nd option is to slide the red box out of the way. If all of that doesn’t work 70.

  39. Terry Bolduc on November 30, 2018 at 4:45 am

    My fifth graders are loving the Esti-Mysteries. I have a group of students who leave my classroom for math Enrichment 3 out of the four days a week when I do them with the rest of the class and they have asked me if I can find another time for them to do the mysteries they’ve missed. Engaging and educational – winning combination. Thank you so much for sharing everything that you do on your Blog.

    • stevewyborney@gmail.com on December 6, 2018 at 6:41 am

      Thank you, Terry! I really appreciate it!

  40. Trish on November 29, 2018 at 3:40 pm

    Thank you! Tried these on a whim today with sixth graders. Only did the first two; they cheered when they got them correct. They want to make their own. Thanks for making 32 kids and one teacher smile big today!

    • stevewyborney@gmail.com on December 6, 2018 at 6:41 am

      I appreciate the comment. You returned the smile to me with your words!

  41. john Oberman on November 19, 2018 at 3:27 am

    Excellent

  42. john Oberman on November 19, 2018 at 3:26 am

    Superb and challenging.

  43. Patricia on November 16, 2018 at 6:48 pm

    We just did Esti-Mysteries at SCCTM with the closing keynote! Trying it in my classroom Monday morning!

  44. Christina on November 16, 2018 at 3:58 pm

    Hi Steve,
    Thanks for your amazing blog and the new Esti-Mysteries. I have done all four with my grade 4 students and they love them! All I have to do is put the next one up and they get psyched about math. Please keep posting them! My next step is to have my students create their own and share with other classes.

    Thanks,
    Christina

    • Erin on December 12, 2018 at 10:24 pm

      I am doing just this- students are using technology, math, and reasoning to create and post their own! (They are on a mission to “stump” the other students..wow!

  45. Laura Vittum on November 15, 2018 at 9:16 am

    You inspired one of my students to make her own!

  46. Nicola on November 14, 2018 at 4:41 am

    Used this today with my Year 1 class – they loved it. Lots of thinking about the 3s counting pattern and great discussion about how you can document your initial options and then work systematically to cross them off as each new clue helps to lead to the answer. I loved it too!

  47. Christina M Caceres on November 13, 2018 at 12:10 pm

    I did this as a spur of the moment with my kids after reading your email about them. They were a hit!!! My students were on the edge of their seats waiting for their next clue and the discussion that emerged from two potential “right” answers was priceless. Based on the image, which is reasonable? I cannot wait to try the next one.

  48. Jesse Goodglass on November 13, 2018 at 11:11 am

    Love it! Tried it this morning with my 4th graders and they had a blast figuring it out. Thanks so much for these resources you are putting together. They are fantastic opportunities for building number sense through visual representations. Thanks again!

  49. Beth Drake on November 13, 2018 at 11:05 am

    Hi There,
    My 5th graders loved it so much that they were begging for more:) It pushed them to think and they loved it.. Thanks

  50. Michelle on November 13, 2018 at 10:02 am

    My students loved it! There were so many things to unpack, multiples, even/odd, etc. They immediately wanted to do another one when we were finished! Thank you so much, can’t wait for more!

  51. Bev Bolnick on November 13, 2018 at 8:21 am

    HI, Have you posted Esti 2 yet?

    • stevewyborney@gmail.com on November 19, 2018 at 6:53 am

      Yes, 1-4 are posted, and I’m planning to post #5 tonight. Thank you!

  52. Meghan on November 13, 2018 at 8:05 am

    Awesome new resource! Thank you

  53. Margot on November 13, 2018 at 2:41 am

    My class were so excited to do the first one today Steve. Thank you for your fantastic resources.

  54. Tracy Keirns on November 12, 2018 at 8:30 pm

    We did your first Esti-Mystery today and the students LOVED using the clues to figure out the answer! Thank you so much for sharing all of your resources with us. The students get so excited when they know we are going to “play” one of your math activities.

  55. Vicky Kennard on November 12, 2018 at 2:42 pm

    Love this idea. Can see howe after a few of these the students will really see how to estimate rather than guess.

  56. Kristin Tupper on November 12, 2018 at 2:12 pm

    This looks great! I can’t wait to try this tomorrow. Thank you again for another wonderful free resource!

  57. Tamara Stamey on November 12, 2018 at 12:47 pm

    Thank you for another great task that helps to make math visible and allows for discourse! Looking forward to future esti-mystery posts!

  58. Evan Engwall on November 12, 2018 at 9:13 am

    Hi Steve,

    I love the Esti-Mystery (as well as your other resources)! I’ve been using them with my students and sharing them with my colleagues.

    I was thinking that 15 would technically be a correct answer to the first Esti-Mystery—but only if you don’t try to count the objects, since there are obviously more that 15. Hopefully, this will generate a friendly little math fight or two…

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