Fun Mystery Unit Activities – Let Your Kids Think Like Detectives!

Mystery activities = fun! Let your kids think like detectives. They’ll love cracking codes, experimenting with invisible ink, fingerprinting, making observations, and more! At home or in the classroom, add some excitement.

Ms. Sneed Adds Some Activities to Her Mystery Unit

Our favorite fourth grade teacher, Ms. Sneed, sat at the computer with her co-teacher. “I’d like to improve our mystery lesson plans,” she said. “We begin with inference activities and short mysteries. Then we move to novel studies. We even have some writing projects. What would complete this mystery genre study?”

“Can I make a case for some detective activities?” asked Mr. Frank.

“Hey, that sounds like a lot of fun!”

Encourage Kids to Become Observant

“First, how can we train them to be more observant?” Ms. Sneed asked. “When they read, the clues blow right over their heads.”

“Hmm, how about challenging them to notice things? For example, we could move something in the classroom each day. We could also see if they remember what their teacher was wearing.”

“Great idea! These observation games won’t even need any materials.”

Get your kids to think like detectives with these simple classroom activities. They're perfect for third, fourth, and fifth grade. Why not add them to your mystery unit?

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“Let’s make a list of classroom and online games,” said Mr. Frank. With just a little searching, the teachers chose this set of observation games:

  1. Move five objects in the classroom each day. How many can each child notice?
  2. Go to a place in the classroom where the kids can’t see you. Ask questions about your eye color, the clothing you’re wearing, etc.
  3. Arrange 30 items on a tray. Let the students look at it for 30 seconds. Then take the tray away. How many items can they remember?
  4. For some online fun, visit CIA Kids Zone. Take the Photo Analysis Challenge and play Memory.

“When kids are more observant, they’re better readers,” said Ms. Sneed. “These observation activities are fun – and will be well worth the time.”

Let Your Little Detectives Crack Secret Codes

Mr. Frank commandeered the computer and began searching on Teachers pay Teachers. “Hey, look at this set of mystery activities for kids. It includes secret codes.”

“Yes, our students would love these worksheets. Let’s try them.”

Her teaching partner added them to the cart.

Enhance your mystery unit with these secret codes. Kids in third, fourth, and fifth grade love them!

Include Invisible Ink in Your Mystery Activities

Ms. Sneed clicked on the resource preview. “The kids can also experiment with invisible ink.” She read on.

  • Method 1 – Stack two pieces of paper on the table. Write a message on the top paper, pressing firmly. Then remove the top sheet. To see what was written, lightly shade the bottom sheet with a pencil.
  • Method 2 – First, write on paper with a white crayon. Brush with watercolor paint to discover what was written.
  • Method 3 – Mix equal amounts of baking soda and water in a bowl. Next, write on paper with a Q-tip. Dry. Brush with grape or cranberry juice to discover what was written.

Your third grade, fourth grade, and fifth grade students will love these invisible ink activities. Let them try all three methods!


“Look at this,” said Ms. Sneed. “Fingerprinting! It’s as easy as loop, whorl, and arch! Our kids will feel like real detectives when they take fingerprints. You can use an ink pad or simple pencil lead.”

Let your third, fourth, and fifth grade students try fingerprinting during your mystery unit. Kids love detective activities!

“Here’s a good tip, too,” Mr. Frank added. “For clear fingerprints, use the pencil lead method. Then, instead of pressing directly onto paper, stick clear tape on the fingertip. Peel off and stick tape on paper.”

Add Logic Puzzles to Your Mystery Activities

“To solve mysteries, detectives must think logically. Similarly, to understand mystery stories, kids must think logically. These logic puzzles will help them develop deductive reasoning,” Mr. Frank continued.

“Yep, and we can also give them some online puzzles to solve. Our students will love all of this!”

Every mystery unit needs logic puzzles. Let your third, fourth, and fifth grade students try some.

Build Your Mystery Unit with Reading Activities, Novels, and Writing

“Well,” said Mr. Frank, “our students will surely learn how to think like detectives. Now let’s work on reading and writing.”

“In addition to these fun mystery activities, this TpT seller has a set of mystery reading passages, writing activities, and even a classroom CSI simulation,” said Ms. Sneed. “Let’s take a look!”

Enjoy Teaching

Over the course of her career, Ms. Sneed realized that there were 6 steps to enjoy teaching. In order to survive, she had to organize, plan, and simplify. Then, to thrive, Ms. Sneed needed to learn, engage, and finally – dive in! Follow the Fabulous Teaching Adventures of Ms. Sneed and learn how you can enjoy teaching too.

To support distance learning, editable Google Slides are now included in Read, Write, and Think Like a Detective.

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