Idea Detective Worksheet
Idea Detective: Case File #1
Read closely • Find the big idea • Spot the supporting details
Target Accuracy 70% Goal (4 of 5 Clues)
Detective Name:
Date:
Score:
Detective Clue: The Main Idea is what the whole text is mostly about. Supporting Details are smaller facts that prove or explain the big idea!
Evidence Passage
Hero Dogs on the Job
Lexile 4th Grade
1 Many dogs are fun pets, but some dogs have special jobs that help people every day. These brave working dogs use their sharp senses and training to protect, guide, and rescue humans in need.
2 First, guide dogs help people who cannot see by safely leading them around obstacles, across busy streets, and into shops. Next, search-and-rescue dogs use their powerful noses to find lost hikers in the woods or mountains.
3 Finally, therapy dogs visit hospitals and nursing homes to bring calm and smiles to sick patients. Working dogs are truly important helpers that make our world safer and brighter.
CLUE 1
Identify the Main Idea of the Text
1. What is this passage mostly about? (Choose one)
A How to teach a new puppy how to sit and fetch a ball.
B Working dogs have important jobs that help and protect people.
C Why hospitals only allow therapy dogs in certain rooms.
2. Complete the sentence frame in your own words:
Sentence Starter: "The main idea of this text is that helper dogs..."
Idea Detective • Reading Comprehension Mastery Turn page for Supporting Details Clues → Page 1 of 2
Case File #1: Evidence Organizer & Checks
Case: Hero Dogs on the Job
CLUE 3
Supporting Detail Evidence Hunt
Find 3 facts from the text that support the main idea
The Main Idea Umbrella
"Some dogs have special jobs that help and protect people."
A Detail 1: Guide Dogs
How do they help?
Paragraph 2 evidence
B Detail 2: Rescue Dogs
How do they help?
Paragraph 2 evidence
C Detail 3: Therapy Dogs
How do they help?
Paragraph 3 evidence
CLUE 4
Which supporting detail from the text proves dogs have a great sense of smell?
A Search-and-rescue dogs use powerful noses to find lost hikers in the mountains.
B Therapy dogs visit patients in quiet hospital rooms.
C Many people enjoy keeping fluffy dogs as family pets at home.
CLUE 5
Which sentence does NOT support the main idea that dogs help people?
A Guide dogs lead people safely across busy streets.
B Therapy dogs comfort patients who feel lonely or stressed.
C Some dogs like to chew on squeaky rubber toys on the living room rug.
Mastery Level Tracker (70%+ Accuracy Target)
Check off each solved clue. Reach at least 4 of 5 for 80% Detective Mastery!
1
Clue 1
2
Clue 2
3
Clue 3
4
Clue 4
5
Clue 5
Total: / 5
Goal: 4/5 (80%) ✅
Idea Detective • Reading Comprehension Mastery Case Complete! Page 2 of 2
Deep Sea Glowers Worksheet
Idea Detective: Case File #2
Read closely • Find the big idea • Spot the supporting details
Target Accuracy 70% Goal (4 of 5 Clues)
Detective Name:
Date:
Score:
Detective Clue: The Main Idea is the core message of the whole text. Supporting Details are facts that prove why that main idea is true!
Evidence Passage
Creatures That Glow in the Deep
Lexile 4th Grade
1 Deep beneath the ocean surface, sunlight cannot reach. Even in total darkness, many unusual sea animals make their own glowing light to help them survive in the cold water.
2 First, the anglerfish has a glowing pole on its head that dangles like a tiny lamp. Curious little fish swim near the light, and the anglerfish snaps them up for dinner. Next, lanternfish have glowing bellies that hide them from bigger predators swimming below.
3 Finally, deep-sea jellyfish can blast bright flashes of blue light to startle hungry attackers so the jellyfish can escape. Living lights give deep ocean creatures special powers to stay alive.
CLUE 1
Identify the Main Idea of the Text
1. What is this passage mostly about? (Choose one)
A Why ocean water becomes colder and darker the deeper a diver swims.
B Deep ocean animals use their own glowing light in different ways to survive.
C How scientists build submarines to study giant octopuses.
2. Complete the sentence frame in your own words:
Sentence Starter: "The main idea of this text is that glowing light helps sea animals..."
Idea Detective • Reading Comprehension Mastery Turn page for Supporting Details Clues → Page 1 of 2
Case File #2: Evidence Organizer & Checks
Case: Creatures That Glow in the Deep
CLUE 3
Supporting Detail Evidence Hunt
Find 3 facts from the text that support the main idea
The Main Idea Umbrella
"Deep sea animals produce their own glowing light to help them survive."
A Detail 1: Anglerfish
How does the light help?
Paragraph 2 evidence
B Detail 2: Lanternfish
How does the light help?
Paragraph 2 evidence
C Detail 3: Jellyfish
How does the light help?
Paragraph 3 evidence
CLUE 4
Which supporting detail proves that light can help a sea creature catch food?
A Curious fish swim near the anglerfish's glowing lamp and get eaten.
