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Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
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Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game
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What others say

"I am very pleased with this purchase. The resource is thoughtfully designed, easy to follow, and aligned well with my instructional goals. My students responded positively, and I will definitely use it again."
star
Chandra S.
"My students loved solving the riddles to crack the math mystery. Very engaging way to reinforce math skills."
star
Tanya S.

Description

Back to School Math Mystery: the Case of The School Invaders -3rd Grade Edition.

Students must review math skills from the previous grade to help get rid of the stinky, slimy Geometron aliens invading Mathhattan Elementary School!


Easy prep!

  • Printable PDF - print, copy, solve!
  • Digital worksheets with Google Slides or EASEL


Optional video hook included for introducing the case!

CLICK HERE FOR VIDEO HOOK! or check out in the preview section.

⭐Due to several requests, now there is the option to use a video hook that says TARGET: 'Your School' instead of TARGET: Mathhattan Elementary. I've added an editable story page for you to add your school's name in the reading section too.

Ending Video Clip also included to wrap up the mystery!

>> UPDATE: The videos now come with voiceovers to narrate the text

-----------------------------------------------------------------------------------------------

Students must use their math skills to unlock clues. The clues will help them eliminate locations to find where the aliens' transponder is!

Math Skills Required to Unlock Clues

There are five clues to crack to solve the mystery:

  • Clue 1: Mental Addition (Numbers 1-20)
  • Clue 2: Place Value of the Underlined Digit (Ones, Tens, Hundreds)
  • Clue 3: Subtraction (Numbers 1-20)
  • Clue 4: Comparing and Ordering Numbers (Numbers 1-60)
  • Clue 5: Even or Odd Numbers

Students must use critical thinking skills to figure out what the clue is telling them to eliminate from the list of possibilities.

----------------------------------------------------------------------------------------------

Multiple Uses

- Consolidation

- Practice and Review

- Math Centers

- Early Finishers

- Substitute Teachers

- Assessment for learning

- Homework

-----------------------------------------------------------------------------------------------


How long will this activity take?

Time to complete varies depending on your student's familiarity with the math mystery format and the skills required to unlock clues. You can pace it out by completing one clue a day --> there are five clues!

-----------------------------------------------------------------------------------------------

- If you would like more challenging math skills, select a higher grade level version of this mystery.

- If you would like a set of easier math skills, select a lower grade level version of this mystery.

This Back to School Math Mystery activity is also available for the other grade levels listed below:

Case of the School Invaders - Grade 1

Case of the School Invaders - Grade 2

Case of the School Invaders - Grade 3

Case of the School Invaders - Grade 4

Case of the School Invaders - Grade 5

Case of the School Invaders - Grade 6

----------------------------------------------------------------------------------------------

Add extra motivation with this Detective Rank Chart Download the Mystery Record & Rank Chart FREEBIE HERE

----------------------------------------------------------------------------------------------

Bundle and Save!

COMPLETE Math Mystery Bundle for GRADE 3

HOLIDAY Math Mysteries Bundle Pack GRADE 3

SKILLS Math Mystery Bundle (3rd Grade)

SEASONS Math Mystery Bundle Pack (GRADE 3)

----------------------------------------------------------------------------------------------------------------

Not sure what a math mystery is? CLICK HERE to watch a video about Math Mysteries

TRY A FULL FREE MATH MYSTERY HERE (GRADES 1 - 6 DIFFERENTIATED BUNDLE)


Browse the 3rd Grade Range:

>>Download the FREE 3rd Grade Checklist here:<<

>> CLICK HERE to follow my store <<

-------------------------------------------------------------------------------------------------

For more ideas, activities, and resources, follow my store (by clicking the little green star) to stay updated on new releases. We can also stay connected via:

Blog

Pinterest

Facebook

Instagram @mrsjsresourcecreations

__________________________________________________________________

>>CLICK HERE to follow my store <<

_________________________________________________________________

Thank you!

Mrs. J.

© 2018

Report this resource to TPT
Reported resources will be reviewed by our team. Report this resource to let us know if this resource violates TPT's content guidelines.
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Back to School Math Mystery Activity - 3rd Grade Beginning of the Year Game

Mrs J's Resource Creations
41.6k Followers
$4.95

Highlights

Digital downloads
Grades icon
Grades
Standards icon
Standards
Pages
16
Answer Key
Included

What others say

"I am very pleased with this purchase. The resource is thoughtfully designed, easy to follow, and aligned well with my instructional goals. My students responded positively, and I will definitely use it again."
star
Chandra S.
"My students loved solving the riddles to crack the math mystery. Very engaging way to reinforce math skills."
star
Tanya S.

Save even more with bundles

CSI Math Mysteries for the holidays! 3rd Grade Edition. These fun math mystery activities will get your students excited about doing math review! Save time and money with this Math Mystery HOLIDAY bundle for Grade 3!Easy prep! Just Print &amp; Solve! Or go paperless with the new Google Slides option
Price $96.70Original Price $138.15Save $41.45
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Math Mysteries COMPLETE 3rd Grade Collection! This complete Math Mystery bundle contains all of my math mysteries for Grade 3 up to date! Make math fun and exciting with these engaging activities that will motivate even some of your most reluctant learners.Easy prep! Just Print &amp; Solve! Or go pa
Price $235.43Original Price $336.35Save $100.92
72
Mrs. J's Math Mystery collection from 1st to 6th grade.Grab all of the math mysteries to engage and motivate your students and differentiate across grade levels! FAQ: Will I be adding more math mysteries to this bundle?A: Yes, I will add new 1st-6th Grade Math Mysteries to this bundle until it reach
Price $1046.48Original Price $1745.75Save $699.27
368

Description

Back to School Math Mystery: the Case of The School Invaders -3rd Grade Edition.

Students must review math skills from the previous grade to help get rid of the stinky, slimy Geometron aliens invading Mathhattan Elementary School!


Easy prep!

  • Printable PDF - print, copy, solve!
  • Digital worksheets with Google Slides or EASEL


Optional video hook included for introducing the case!

CLICK HERE FOR VIDEO HOOK! or check out in the preview section.

⭐Due to several requests, now there is the option to use a video hook that says TARGET: 'Your School' instead of TARGET: Mathhattan Elementary. I've added an editable story page for you to add your school's name in the reading section too.

Ending Video Clip also included to wrap up the mystery!

>> UPDATE: The videos now come with voiceovers to narrate the text

-----------------------------------------------------------------------------------------------

Students must use their math skills to unlock clues. The clues will help them eliminate locations to find where the aliens' transponder is!

Math Skills Required to Unlock Clues

There are five clues to crack to solve the mystery:

  • Clue 1: Mental Addition (Numbers 1-20)
  • Clue 2: Place Value of the Underlined Digit (Ones, Tens, Hundreds)
  • Clue 3: Subtraction (Numbers 1-20)
  • Clue 4: Comparing and Ordering Numbers (Numbers 1-60)
  • Clue 5: Even or Odd Numbers

Students must use critical thinking skills to figure out what the clue is telling them to eliminate from the list of possibilities.

----------------------------------------------------------------------------------------------

Multiple Uses

- Consolidation

- Practice and Review

- Math Centers

- Early Finishers

- Substitute Teachers

- Assessment for learning

- Homework

-----------------------------------------------------------------------------------------------


How long will this activity take?

Time to complete varies depending on your student's familiarity with the math mystery format and the skills required to unlock clues. You can pace it out by completing one clue a day --> there are five clues!

-----------------------------------------------------------------------------------------------

- If you would like more challenging math skills, select a higher grade level version of this mystery.

- If you would like a set of easier math skills, select a lower grade level version of this mystery.

This Back to School Math Mystery activity is also available for the other grade levels listed below:

Case of the School Invaders - Grade 1

Case of the School Invaders - Grade 2

Case of the School Invaders - Grade 3

Case of the School Invaders - Grade 4

Case of the School Invaders - Grade 5

Case of the School Invaders - Grade 6

----------------------------------------------------------------------------------------------

Add extra motivation with this Detective Rank Chart Download the Mystery Record & Rank Chart FREEBIE HERE

----------------------------------------------------------------------------------------------

Bundle and Save!

COMPLETE Math Mystery Bundle for GRADE 3

HOLIDAY Math Mysteries Bundle Pack GRADE 3

SKILLS Math Mystery Bundle (3rd Grade)

SEASONS Math Mystery Bundle Pack (GRADE 3)

----------------------------------------------------------------------------------------------------------------

Not sure what a math mystery is? CLICK HERE to watch a video about Math Mysteries

TRY A FULL FREE MATH MYSTERY HERE (GRADES 1 - 6 DIFFERENTIATED BUNDLE)


Browse the 3rd Grade Range:

>>Download the FREE 3rd Grade Checklist here:<<

>> CLICK HERE to follow my store <<

-------------------------------------------------------------------------------------------------

For more ideas, activities, and resources, follow my store (by clicking the little green star) to stay updated on new releases. We can also stay connected via:

Blog

Pinterest

Facebook

Instagram @mrsjsresourcecreations

__________________________________________________________________

>>CLICK HERE to follow my store <<

_________________________________________________________________

Thank you!

Mrs. J.

© 2018

Report this resource to TPT
Reported resources will be reviewed by our team. Report this resource to let us know if this resource violates TPT's content guidelines.

Reviews

4.9
Rated 4.88 out of 5, based on 1340 reviews
1340
ratings
5
1,237
4
97
3
6
2
0
1
0
Mostly used with 3rd grade
Reviews
14
85
540
89
31
10
8
1st
2nd
3rd
4th
5th
6th
7th
What customers are saying
Met expectations
100%
Is a great value
98%
Is standards-aligned
100%
All verified TPT purchases
Well done resource
Rated 5 out of 5
May 29, 2026
I am very pleased with this purchase. The resource is thoughtfully designed, easy to follow, and aligned well with my instructional goals. My students responded positively, and I will definitely use it again.
Chandra S.
127 reviews • Washington
Grades taught: PreK, K, 1st, 2nd, 3rd
great resource!
Rated 5 out of 5
May 12, 2026
This was a great resource to review with my students! Thank you!
Jennifer W.
318 reviews • Georgia
Grades taught: 2nd, 3rd, 4th
Student populations: Emerging bilinguals, Learning difficulties
A Fantastic Resource
Rated 5 out of 5
May 4, 2026
Met expectations
Great value
Standards-aligned
Well worth the price. Kids loves these, and are always engaged.
Alison Gert
(TPT Seller)
848 reviews • Outside the United States
Grades taught: 6th, 7th, 8th
Great resource
Rated 5 out of 5
April 26, 2026
Met expectations
Great value
Standards-aligned
This was a fun math activity to get my students excited for the beginning of the school year!
John S.
44 reviews
Grades taught: 3rd, 4th, 5th
Great resource for elementary school kids. Thank you!!
Rated 5 out of 5
March 4, 2026
Great resource for elementary school kids. Thank you!!
Julia T.
232 reviews • Kentucky
Grades taught: 3rd, 4th, 5th
Love these mysteries!
Rated 5 out of 5
February 1, 2026
Met expectations
Great value
Standards-aligned
My class loves these math mysteries - we have so many!
Jennifer Ross
(TPT Seller)
499 reviews • Connecticut
Grades taught: 3rd
Math Mystery
Rated 5 out of 5
January 25, 2026
Met expectations
Great value
Standards-aligned
My students loved solving the riddles to crack the math mystery. Very engaging way to reinforce math skills.
Tanya Smith
(TPT Seller)
150 reviews • California
Grades taught: 3rd
Student populations: Emerging bilinguals
Great Review for 3rd
Rated 5 out of 5
January 18, 2026
Met expectations
Great value
Standards-aligned
This was a great review for my third graders to review any past skills to see where they are!
Rita C.
17 reviews
Grades taught: 2nd, 3rd

Questions & Answers

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Standards

to see state-specific standards (only available in the US).
The numbers 100, 200, 300, 400, 500, 600, 700, 800, 900 refer to one, two, three, four, five, six, seven, eight, or nine hundreds (and 0 tens and 0 ones).
Compare two three-digit numbers based on meanings of the hundreds, tens, and ones digits, using >, =, and < symbols to record the results of comparisons.
Fluently add and subtract within 20 using mental strategies. By end of Grade 2, know from memory all sums of two one-digit numbers.
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