Grade 3Reading: grades 3-4MultiplicationRoundingAdditionSubtractionDivision
The Whispering Woods Treehouse Case
The golden spy walkie-talkie has been swiped from the high shelf of our secret base! The culprit left a trail of mysterious high-tech gear and strange disguises behind. It is up to our spy crew to crack the codes, track the clues, and find out which agent turned rogue before the secret treehouse plans are leaked!
Suspects
Possible suspects
Cross off a row as each clue rules it out. On screen, tap a row.
21 of 21 still in play
| Name | Special Gear | Agent Badge | Writing Hand | Disguise Wig | Distraction |
|---|---|---|---|---|---|
| Cole Casing | Mini Smoke Bombs | Shark Badge | Right-handed notes | Electric Blue Wig | Bubble Wrap |
| Owen Phantom | Mini Smoke Bombs | Falcon Badge | Right-handed notes | Bright Orange Wig | Squeaky Toy |
| Chase Shadow | Mini Smoke Bombs | Tiger Badge | Right-handed notes | Neon Green Wig | Bubble Wrap |
| Cody Black | Decoder Laser Pen | Falcon Badge | Right-handed notes | Electric Blue Wig | Bubble Wrap |
| Luke Wire | Night Vision Goggles | Tiger Badge | Right-handed notes | Neon Green Wig | Shiny Laser Pointer |
| Sam Goggles | Night Vision Goggles | Tiger Badge | Right-handed notes | Neon Green Wig | Squeaky Toy |
| Emma Gizmo | Night Vision Goggles | Bear Badge | Right-handed notes | Neon Green Wig | Squeaky Toy |
| Zoe Frost | Grappling Hook | Cobra Badge | Left-handed notes | Neon Green Wig | Bubble Wrap |
| Eli Agent | Mini Smoke Bombs | Tiger Badge | Right-handed notes | Electric Blue Wig | Bubble Wrap |
| Ava Decoder | Grappling Hook | Shark Badge | Right-handed notes | Neon Green Wig | Bubble Wrap |
| Leo Swift | Super Jet Boots | Shark Badge | Right-handed notes | Electric Blue Wig | Shiny Laser Pointer |
| Mia Whispers | Night Vision Goggles | Tiger Badge | Left-handed notes | Neon Green Wig | Bubble Wrap |
| Max Stealth | Mini Smoke Bombs | Shark Badge | Right-handed notes | Neon Green Wig | Squeaky Toy |
| Jack Tracker | Super Jet Boots | Shark Badge | Left-handed notes | Neon Green Wig | Squeaky Toy |
| Ian Sneak | Night Vision Goggles | Tiger Badge | Right-handed notes | Bright Orange Wig | Shiny Laser Pointer |
| Nancy Drew | Mini Smoke Bombs | Falcon Badge | Right-handed notes | Neon Green Wig | Squeaky Toy |
| Kira Cipher | Decoder Laser Pen | Cobra Badge | Left-handed notes | Electric Blue Wig | Squeaky Toy |
| Maya Blade | Grappling Hook | Cobra Badge | Left-handed notes | Bright Orange Wig | Shiny Laser Pointer |
| Lily Signal | Decoder Laser Pen | Shark Badge | Left-handed notes | Neon Green Wig | Bubble Wrap |
| Ben Scope | Night Vision Goggles | Bear Badge | Right-handed notes | Neon Green Wig | Shiny Laser Pointer |
| Alex Rider | Night Vision Goggles | Cobra Badge | Right-handed notes | Neon Green Wig | Squeaky Toy |
Clue 1
Multiplication facts (1-12)
To open the top-secret gadget drawer, we need to count the rows of spy flashlights.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
T
144
88
81
100
96
28
28
6
96
30
10
44
81
32
30
44
T
144
88
6
100
81
T
144
88
81
8
81
6
33
8
6
10
25
81
12 × 12 =T
8 × 4 =S
11 × 8 =H
11 × 3 =R
9 × 9 =E
5 × 5 =G
11 × 4 =O
5 × 6 =N
4 × 7 =L
2 × 5 =D
3 × 2 =A
10 × 10 =V
8 × 1 =B
12 × 8 =I
0/14 letters found
Clue 2
Rounding
Our fuzzy motion radar only displays rounded numbers, but it will help us trace the agent.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
T
5000
90
600
4000
60
4000
7000
600
6000
T
5000
30
300
9000
T
5000
600
900
9000
T
5000
600
4000
30
70
T
5000
90
T
5000
90
600
70
300
300
70
3000
90
T
5000
90
8000
900
700
Round 4,686 to the nearest thousandT
Round 331 to the nearest hundredR
Round 7,182 to the nearest thousandP
Round 854 to the nearest hundredN
Round 67 to the nearest tenI
Round 9,388 to the nearest thousandO
Round 3,725 to the nearest thousandS
Round 92 to the nearest tenH
Round 7,534 to the nearest thousandA
Round 3,189 to the nearest thousandG
Round 6,273 to the nearest thousandC
Round 61 to the nearest tenU
Round 653 to the nearest hundredD
Round 556 to the nearest hundredE
Round 26 to the nearest tenW
0/15 letters found
Clue 3
Addition
We need to add up all the microchips we recovered from the treehouse floor.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
T
542
295
639
327
849
233
751
639
689
410
751
639
918
895
639
632
282
295
639
774
T
542
295
639
903
689
918
282
918
689
410
751
639
918
552
903
T
542
849
903
250 + 292 =T
290 + 484 =N
592 + 257 =O
190 + 105 =H
205 + 205 =Q
570 + 333 =Y
383 + 249 =D
617 + 301 =A
472 + 217 =S
538 + 357 =L
410 + 229 =E
143 + 139 =W
313 + 438 =U
330 + 222 =K
128 + 199 =R
83 + 150 =G
0/16 letters found
Clue 4
Subtraction
Let us calculate how many water balloons we have left after the practice battle.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
W
717
552
270
371
811
121
834
160
390
896
367
121
834
160
371
270
367
121
552
371
121
107
896
552
552
121
834
423
160
107
811
423
160
552
952 - 235 =W
689 - 266 =I
892 - 340 =E
661 - 391 =F
831 - 20 =U
201 - 80 =N
654 - 287 =A
855 - 21 =D
732 - 342 =T
318 - 211 =G
985 - 89 =R
200 - 40 =S
413 - 42 =O
0/13 letters found
Clue 5
Division facts (1-12) — the last clue
We must split these secret decoder rings equally among our team members to reveal the final clue.
First solve each problem. Then find each answer in the list below and cross that sentence out. One sentence will be left — that's exactly what the villain did!
Step 1 — solve these
8 ÷ 8 = ?
120 ÷ 10 = ?
42 ÷ 6 = ?
20 ÷ 5 = ?
45 ÷ 9 = ?
54 ÷ 6 = ?
33 ÷ 3 = ?
10 ÷ 1 = ?
36 ÷ 12 = ?
64 ÷ 8 = ?
12 ÷ 2 = ?
Step 2 — cross out the sentence with each answer
1.The villain sneaks through the dark forest, then flashes a golden tiger emblem.
2.The villain escapes in a cloud of grey smoke, then leaves a silver falcon feather.
3.The villain sneaks through the dark forest, then drops a plastic toy shark.
4.The villain shines a glowing green beam, then hisses like a wild snake.
5.The villain shines a glowing green beam, then flashes a golden tiger emblem.
6.The villain blasts over the tall wall, then flashes a golden tiger emblem.
7.The villain sneaks through the dark forest, then hisses like a wild snake.
8.The villain blasts over the tall wall, then drops a plastic toy shark.
9.The villain blasts over the tall wall, then hisses like a wild snake.
10.The villain escapes in a cloud of grey smoke, then flashes a golden tiger emblem.
11.The villain blasts over the tall wall, then makes a loud bear growl.
12.The villain escapes in a cloud of grey smoke, then drops a plastic toy shark.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Whispering Woods Treehouse Case
Culprit: Nancy Drew (Mini Smoke Bombs · Falcon Badge · Right-handed notes · Neon Green Wig · Squeaky Toy)
- Clue 1 (Multiplication facts (1-12)): "THE VILLAIN DOES NOT HAVE THE BEAR BADGE"12 × 12 = 144 (T) · 8 × 4 = 32 (S) · 11 × 8 = 88 (H) · 11 × 3 = 33 (R) · 9 × 9 = 81 (E) · 5 × 5 = 25 (G) · 11 × 4 = 44 (O) · 5 × 6 = 30 (N) · 4 × 7 = 28 (L) · 2 × 5 = 10 (D) · 3 × 2 = 6 (A) · 10 × 10 = 100 (V) · 8 × 1 = 8 (B) · 12 × 8 = 96 (I)
- Clue 2 (Rounding): "THE SUSPECT WROTE NOTES WITH THEIR RIGHT HAND"Round 4,686 to the nearest thousand = 5000 (T) · Round 331 to the nearest hundred = 300 (R) · Round 7,182 to the nearest thousand = 7000 (P) · Round 854 to the nearest hundred = 900 (N) · Round 67 to the nearest ten = 70 (I) · Round 9,388 to the nearest thousand = 9000 (O) · Round 3,725 to the nearest thousand = 4000 (S) · Round 92 to the nearest ten = 90 (H) · Round 7,534 to the nearest thousand = 8000 (A) · Round 3,189 to the nearest thousand = 3000 (G) · Round 6,273 to the nearest thousand = 6000 (C) · Round 61 to the nearest ten = 60 (U) · Round 653 to the nearest hundred = 700 (D) · Round 556 to the nearest hundred = 600 (E) · Round 26 to the nearest ten = 30 (W)
- Clue 3 (Addition): "THE ROGUE SQUEALED WHEN THEY SAW A SQUEAKY TOY"250 + 292 = 542 (T) · 290 + 484 = 774 (N) · 592 + 257 = 849 (O) · 190 + 105 = 295 (H) · 205 + 205 = 410 (Q) · 570 + 333 = 903 (Y) · 383 + 249 = 632 (D) · 617 + 301 = 918 (A) · 472 + 217 = 689 (S) · 538 + 357 = 895 (L) · 410 + 229 = 639 (E) · 143 + 139 = 282 (W) · 313 + 438 = 751 (U) · 330 + 222 = 552 (K) · 128 + 199 = 327 (R) · 83 + 150 = 233 (G)
- Clue 4 (Subtraction): "WE FOUND STRANDS OF A NEON GREEN DISGUISE"952 - 235 = 717 (W) · 689 - 266 = 423 (I) · 892 - 340 = 552 (E) · 661 - 391 = 270 (F) · 831 - 20 = 811 (U) · 201 - 80 = 121 (N) · 654 - 287 = 367 (A) · 855 - 21 = 834 (D) · 732 - 342 = 390 (T) · 318 - 211 = 107 (G) · 985 - 89 = 896 (R) · 200 - 40 = 160 (S) · 413 - 42 = 371 (O)
- Clue 5 (Division facts (1-12)): surviving statement (box 2) → Nancy Drew8 ÷ 8 = 1 · 120 ÷ 10 = 12 · 42 ÷ 6 = 7 · 20 ÷ 5 = 4 · 45 ÷ 9 = 5 · 54 ÷ 6 = 9 · 33 ÷ 3 = 11 · 10 ÷ 1 = 10 · 36 ÷ 12 = 3 · 64 ÷ 8 = 8 · 12 ÷ 2 = 6
About this mystery
- Grade level
- Grade 3 math
- Math topics
- Multiplication, Rounding, Addition, Subtraction, Division
- Reading level
- grades 3-4
- Theme
- The Whispering Woods Treehouse Case — set in the Whispering Woods Treehouse
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects