This school year, I’ll be creating and posting 125 new ESti-Mysteries.
Throughout the school year, I’ll add new ones to this blog post – so you can find them all here.
Each time I add a new one, I’ll let blog subscribers know. If you are not subscribed to the blog, you can sign up here.
Blog subscribers will also learn about many other resources that I post throughout the school year.
Thank you for sharing these Esti-Mysteries with colleagues in your school.
Let’s spread the math joy!
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New This Week!
Friday, January 9, 2026
Grades 1-3: ” Circling Numbers”
BONUS NOTE: “Circling Numbers” is a nod to how many of us solve Esti-Mysteries, by circling our estimate when we begin!
FUN BONUS QUESTION: After you finish the Esti-Mystery, and your class discovers that the answer is 45, it will be fun to reveal “This is one of very few Esti-Mysteries where the answer can be seen hiding in the vase.” Can you find it? (It’s in the center, turned slightly, so you can just see it!)

Grades 4-12: ” Factors Exactly”
BONUS NOTE: To solve the final clue, you need to figure out which remaining number has exactly 10 factors and eliminate it. The 3 final numbers are: 36, 48, and 60
Students could either find all the factors of each number, or approach it a different way: 36 is a square number, so it must have an odd number of factors. Factors of 60 include: 1, 2, 3, 4, 5, 6 … so there must be more than 10 factors. Of course, there are also many other ways to to approach it.
BONUS QUESTIONS: A bonus question could be, “Why does 36 have an odd number of factors? Are there any other numbers that have an odd number of factors? What do those numbers have in common?

Wednesday, January 7, 2026
Kindergarten: “Number Pegs”
BONUS NOTE: The “Number Pegs” Esti-Mystery offers a really fun follow-up moment. After students finish the Esti-Mystery, and learn that the total is 15, you can ask “If you look closely at the picture, what do you notice about the number 15?”
(It is the one number missing from the number pattern in the middle.)

Grades 1-2: “Do You See the Final Clue?”
BONUS NOTE: “Do You See the Final Clue” has a fun variation! The 4th clue will ask you to find a digit seen in the top of the picture, but to save that information until the next clue. It’s one of the few Esti-Mystery clues that does not eliminate any numbers – at least not right away!

Grades 3-8: “Clearly Visible”
BONUS NOTE: The “Clearly Visible” Esti-Mystery has a fun twist! When you reach the final clue, there will be 3 numbers remaining. The last clue will tell you to look at the picture where you’ll clearly see one of those numbers to eliminate.

Monday, January 5, 2026
Grades 1-3: “Many Beads”

Grades 4-12: “The Bead Scoop”

Tuesday, December 16, 2025
Kindergarten: “Colorful Beads”

Grades 1-2: “The Matching Digits”

Grades 3-8: “Striped Beads”

Friday, December 5, 2025
Grades 1-3: “Five Clues That All Use The Number Five”

Grades 4-12: “Prime Time”

Tuesday, December 2, 2025
Kindergarten: “Pink and Orange”

Grades 1-2: “Thin Vase”

Grades 3-8: “Not Next to a Ten”

Wednesday, November 19, 2025
Kindergarten: “Weather”

Grades 1-2: “Sunshine”

Grades 3-8: “The Consecutive Pair Storm”

Friday, November 21, 2025
Grades 1-3: “Raindrop”

Grades 4-12: “Look Through the Glass to See the Clue”

Friday, November 14, 2025
Kindergarten: “Bird Whistles”

Grades 1-2: “Tweet”

Grades 1-3: “Warble”

Grades 3-8: “The Number of Colors is a Clue”

Grades 4-12: “Nest-i-Mystery”

Tuesday, November 4, 2025
Kindergarten: “Shapes”

Grades 1-2: “Several Shapes”

Grades 3-8: “Layers of Shapes”

Friday, November 7, 2025
Grades 1-3: “Shapes in the Vase”

Grades 4-12: “Painted Shapes”

Tuesday, October 28, 2025
Kindergarten: “Scrolls”

Grades 1-2: “Tiny Scrolls”

Grades 3-8: “Consecutive Numbers”

Thursday, October 30, 2025
Grades 1-3: “Unrolling the Clues”

Grades 4-12: “Not Double”

Tuesday, October 21, 2025
Kindergarten: “Up and Down”

Grades 1-2: “Grooves”

Grades 3-8: “Stripes”

Friday, October 24, 2025
Grades 1-3: “Lines”

Grades 4-12: “Sticky”

Tuesday, October 14, 2025
Kindergarten: “Did You Draw a Top After Clue #3?

Grades 1-2: “Tops on Tops”

Grades 3-8: “The Pairs Will Last Until the Final Clue”

Thursday, October 16, 2025
Grades 1-3: “Colorful Tops”

Grades 4-12: “Multiple Clues”

Tuesday, October 7, 2025
Kindergarten: “Round”

Grades 1-2: “Funny Wheels”

Grades 3-8: “Not Between the Numbers”

Thursday, October 9, 2025
Grades 1-3: “Colorful Wheels”

Grades 4-12: “Not By a Square”

New to Esti-Mysteries? Here is a YouTube Playlist of Tips
Take a look at my YouTube Playlist of Esti-Mystery Tips.

September 30 – October 1
Tuesday, September 30, 2025
Kindergarten: “Counting Chairs”

Grades 1-2: “The Time the Die Sat Down”

Grades 3-8: The Time When the Clue Sat on a Chair

Thursday, October 1, 2025
Grades 1-3: “Stacking Chairs”

Grades 4-12: “Right Next to a Prime Number”

I hope you enjoy the new Esti-Mysteries this year! I hope they bring joy and rich math talk to your classroom!
All my best,
Steve
Esti-Mysteries from Past Years
2024-2025 110 New Esti-Mysteries

2023-2024 100 New Esti-Mysteries

2022-2023 170 New Esti-Mysteries

2021-2022 150 New Esti-Mysteries



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