Step Detectives Supported Worksheet Guided Tier Math Case Files • 3rd Grade
Step Detectives: Two-Step Clues
Name:
Date:
Detective Strategy: Every two-step problem has a hidden first question you must solve before answering the main question!
Two Clues = Two Steps
1
Case #1: The Muffin Sale Mystery
Bakery Clue
Maya baked 48 blueberry muffins in the morning and 35 strawberry muffins in the afternoon. At the school bake sale, 56 muffins were sold. How many muffins does Maya have left?
Step 1: Hidden Question
How many total muffins did Maya bake?
Choose: Add (+) Subtract (−)
Visual Model / Sketch space:
Equation: _______________ Total = _____
Step 2: Main Question
How many muffins are left after selling 56?
Choose: Add (+) Subtract (−)
Show your math work:
Equation: _______________ Answer: _____ muffins
2
Case #2: The Library Books Return
Library Clue
The school library had 75 mystery books on the shelf. In the morning, students checked out 28 mystery books. In the afternoon, a teacher returned 14 mystery books. How many mystery books are on the shelf now?
Step 1: Hidden Question
How many books were left after checkouts?
Choose: Add (+) Subtract (−)
Visual Model / Sketch space:
Equation: _______________ Books left = _____
Step 2: Main Question
How many books are on the shelf now?
Choose: Add (+) Subtract (−)
Show your math work:
Equation: _______________ Answer: _____ books
Step Detectives • Case Files 1 & 2 Turn page for Cases 3 & 4 →
Step Detectives: Continued Clues
Case Files #3 and #4 • Show all your steps
Detective:
3
Case #3: The Zoo Flamingo Count
Wildlife Clue
A wildlife park had 64 flamingos wading in the lagoon. A sudden gust of wind caused 19 flamingos to fly away. A few minutes later, 23 new flamingos landed. How many flamingos are in the lagoon now?
Step 1: Hidden Question
How many flamingos stayed in the lagoon?
Choose: Add (+) Subtract (−)
Tape diagram / visual sketch:
Equation: _______________ Flamingos left = _____
Step 2: Main Question
How many total flamingos are there now?
Choose: Add (+) Subtract (−)
Show your math work:
Equation: _______________ Answer: _____ flamingos
4
Case #4: The Arcade Ticket Prize
Prize Clue
Ethan scored 45 tickets playing Ring Toss and 52 tickets playing Skee-Ball. He then spent 68 tickets to get a plush bear at the prize counter. How many tickets does Ethan have remaining?
Step 1: Hidden Question
How many tickets did Ethan win in all?
Choose: Add (+) Subtract (−)
Tape diagram / visual sketch:
Equation: _______________ Total won = _____
Step 2: Main Question
How many tickets are left after buying the bear?
Choose: Add (+) Subtract (−)
Show your math work:
Equation: _______________ Answer: _____ tickets
Detective Case Checklist
Found hidden question
Drew models & equations
Wrote label with my answer
Step Detectives • Case Files 3 & 4 Case Closed! Great detective work!
Step Detectives Challenge Worksheet Master Investigator Tier Math Case Files • 3rd Grade Advanced
Step Detectives: Master Challenges
Name:
Date:
Master Directive: Beware of distracting extra data! Write a single equation using a letter (variable) for the unknown, and justify your answer.
3-Digit Operations
1
Case #201: The Wildlife Sanctuary Audit
Extraneous Data Clue
The Pine Ridge Wildlife Sanctuary had 438 whitetail deer and 275 elk on the reservation. The sanctuary employs 16 rangers. During the winter freeze, 189 deer migrated south to the valley. How many total animals (deer and elk) remained on the reservation?
Analysis & Equation
Cross out unnecessary information in the problem. Then write an equation for the remaining animals using a for the unknown:
Equation: ___________________________________
Reasonableness Check
Round numbers to the nearest hundred to estimate the total remaining animals before solving:
Estimate: _____ + _____ − _____ ≈ _____
Show Exact 2-Step Work: Show regrouping clearly
State your findings: Final Answer: ________________ animals remain
2
Case #202: The Multi-Class Bookathon
Comparative Reasoning
Grade 3 hosted a reading marathon. Room 12 read 325 pages on Monday. Room 14 read 78 fewer pages than Room 12. Room 16 read 94 more pages than Room 14. How many total pages did Room 14 and Room 16 read combined?
Step 1 & Step 2 Calculations
Find Room 14 first, then Room 16:
Room 14: _____ pages Room 16: _____ pages
Final Step & Conclusion
Add Room 14 and Room 16 together:
Total Combined: ________________ pages
Master Investigator • Cases 201 & 202 Turn page for Dual-Method Proof & Mission Creator →
Step Detectives: Advanced Investigations
Case Files #203, #204 & Case Creator Mission
Lead Investigator:
3
Case #203: The Central Warehouse Depot (Dual-Method Proof)
Across Zeros
A technology distribution depot started Monday morning with exactly 700 laptops in stock. On Tuesday, they shipped out 264 laptops. On Wednesday, they shipped out another 188 laptops. Prove how many laptops remain using two different methods :
Step Detectives Answer Keys Teacher Reference Full Solutions & Scaffolding Guide
Step Detectives: Supported Tier Answer Key
CCSS 3.OA.D.8 Two-Step Word Problems (±)
1 Case #1: The Muffin Sale Mystery (Maya's Muffins) Answer: 27 muffins
Step 1 (Operation: Addition [+]):
\(48 + 35 = 83\) muffins baked in total
Regrouping: \(8 + 5 = 13\) ones (1 ten, 3 ones); \(1 + 4 + 3 = 8\) tens.
Step 2 (Operation: Subtraction [−]):
\(83 - 56 = 27\) muffins left
Regrouping: Unbundle 1 ten to make 13 ones. \(13 - 6 = 7\); \(7 - 5 = 2\).
Scaffold Tip: If students subtract 56 from 48 first, guide them back to the chronology: muffins must be baked before they can be sold.
2 Case #2: The Library Books Return Answer: 61 mystery books
Step 1 (Operation: Subtraction [−]):
\(75 - 28 = 47\) books remaining on shelf
Regrouping: \(15 - 8 = 7\); \(6 - 2 = 4\) tens.
Step 2 (Operation: Addition [+]):
\(47 + 14 = 61\) books on shelf now
Regrouping: \(7 + 4 = 11\) ones (1 ten, 1 one); \(1 + 4 + 1 = 6\) tens.
Scaffold Tip: Emphasize that "checked out" means books leave (−), while "returned" means books come back (+).
3 Case #3: The Zoo Flamingo Count Answer: 68 flamingos
Step 1 (Operation: Subtraction [−]):
\(64 - 19 = 45\) flamingos stayed
Regrouping: \(14 - 9 = 5\); \(5 - 1 = 4\) tens.
Step 2 (Operation: Addition [+]):
\(45 + 23 = 68\) flamingos in lagoon
No regrouping required: \(5 + 3 = 8\) ones; \(4 + 2 = 6\) tens.
Alternative Path: \(64 + 23 = 87\), then \(87 - 19 = 68\). Point out that both orders yield the same accurate final total.
4 Case #4: The Arcade Ticket Prize Answer: 29 tickets
Step 1 (Operation: Addition [+]):
\(45 + 52 = 97\) total tickets won
No regrouping: \(5 + 2 = 7\) ones; \(4 + 5 = 9\) tens.
Step 2 (Operation: Subtraction [−]):
\(97 - 68 = 29\) tickets remaining
Regrouping: \(17 - 8 = 9\); \(8 - 6 = 2\) tens.
Visual Model Note: Students should draw a two-part bar for \(45 + 52\), then cross out a section of 68 to reveal the remainder.
Supported Tier Teacher Key • Cases 1–4 Turn for Master Challenge Solutions →
Teacher Reference Advanced Multi-Step Analysis
Step Detectives: Master Challenge Answer Key
3-Digit Operations Variables & Dual Proofs
201 Wildlife Sanctuary Audit Answer: 524 animals
Extraneous Info:
"16 park rangers" is unrelated to animal counts.
