April 1st Grade Math Mystery Worksheets: Alien Ambush

Description Make your April math block “out of this world” with these April 1st grade math mystery worksheets featuring the Case of the April Alien Ambush! This engaging activity combines a high-stakes investigation with agent gnomes, alien technology, and a “Color Restoration” theme to keep engagement high all month long. Students read the mystery story about a stolen Chromatic Core from the Gnomes in Black (G.I.B.) agency. They must complete five math worksheets to unlock clues and eliminate suspects until only the imposter remains. It’s a targeted review of 1st Grade Common Core standards that feels like an exciting game!   ⭐ The Case of the April Alien Ambush (1st Grade Edition) Both printable and digital worksheet options are provided for maximum flexibility in your classroom. Your student detectives must use critical thinking and deductive reasoning to solve who should be eliminated from the list after each clue message is unlocked.   ⭐ Optional Videos An exciting animated video hook is provided to set the stage and engage your student detectives! You can check it out here <click to view> A celebratory ending video clip is also included to wrap up the activity and reveal the culprit once the case is solved.   ⭐ Preparation & Digital Options Easy Prep Printable Version: Simply print and copy the PDF worksheets, and your student detectives are ready to solve! Perfect for sub tubs. Digital Option: A Google Slides version is included for paperless classrooms. Find the link in the Teacher Instructions section of your download to assign it via Google Classroom. (Note: Students must be in ‘edit’ mode to enter answers). Interactive Displays: Watch the videos on a smartboard, tablet, or computer to set the stage and celebrate the win.   ⭐ Math Skills Required to Unlock Clues There are five mission clues to crack to solve the mystery, each focusing on core 1st-grade math standards: Clue 1: Addition and Subtraction within 20 Mastery (including a mix of missing addends, and adding three single-digit numbers, too) Clue 2: Place Value – Tens and Ones with a fun Alien theme Clue 3: Addition and Subtraction Word Problems (within 20) Clue 4: Comparing Double-Digit Numbers Clue 5: Read and Write Time (o’Clock and Half-Past only)   ⭐ Multiple Uses This Spring/Space-themed activity is versatile and great for: April Math Centers & Stations Spiral Review & Test Prep Early Finishers & Enrichment Homework Assignments Fun Friday Activities   ⭐ Easy Differentiation This mystery is available in other math level packs, so you can pick one that suits your class or homeschool best. Check out my other grade-level editions to “Clue Swap” for students working above or below grade level.   ⭐ Frequently Asked Questions & Extras Looking for more 1st grade resources? Math Mystery Worksheets & Activity Sheets for Teachers For more ideas, activities, and resources, follow my store to stay updated on new releases. We can also stay connected via: Subscribe to my newsletter Pinterest Facebook Thank you! Mrs. J. © 2026