Grade 4Reading: grades 3-4RoundingAdditionSubtractionMultiplicationDivision

The Treehouse Spy Club: Case of the Missing Golden Pineapple

The Golden Pineapple trophy has vanished from the main treehouse cabin! The Head Scout is counting on our Treehouse Spy Club to crack the case, gather the evidence, and identify the Sneaky Thief before the big campfire meetup tonight.

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	Primary Gadget	Secret Base Room	Write Hand	Cap Color	Dropped Candy
Grace	Sound Listener	Secret Wardrobe	Right-handed	Blue Cap	Gummy Bears
Sam	Night Goggles	Lookout Tower	Left-handed	Blue Cap	Sour Worms
Aria	Sound Listener	Underground Tunnel	Right-handed	Red Cap	Bubble Gum
Jax	Night Goggles	Secret Wardrobe	Left-handed	Blue Cap	Gummy Bears
Chloe	Sound Listener	Underground Tunnel	Left-handed	Blue Cap	Bubble Gum
Ben	Laser Pointer	Attic Loft	Right-handed	Green Cap	Bubble Gum
Harper	Laser Pointer	Lookout Tower	Right-handed	Blue Cap	Gummy Bears
Mason	Grappling Hook	Lookout Tower	Right-handed	Green Cap	Bubble Gum
Zoe	Night Goggles	Back Porch	Right-handed	Green Cap	Bubble Gum
Ava	Super Magnifier	Lookout Tower	Right-handed	Red Cap	Sour Worms
Sophia	Super Magnifier	Underground Tunnel	Right-handed	Blue Cap	Gummy Bears
Leo	Night Goggles	Underground Tunnel	Right-handed	Blue Cap	Bubble Gum
Mia	Super Magnifier	Underground Tunnel	Right-handed	Green Cap	Sour Worms
Wyatt	Laser Pointer	Secret Wardrobe	Right-handed	Blue Cap	Sour Worms
Jack	Grappling Hook	Back Porch	Right-handed	Green Cap	Bubble Gum
Owen	Super Magnifier	Back Porch	Right-handed	Blue Cap	Gummy Bears
Lily	Laser Pointer	Lookout Tower	Left-handed	Blue Cap	Sour Worms
Emma	Night Goggles	Attic Loft	Left-handed	Blue Cap	Gummy Bears
Luke	Grappling Hook	Lookout Tower	Left-handed	Blue Cap	Gummy Bears
Maya	Grappling Hook	Attic Loft	Right-handed	Blue Cap	Gummy Bears
Eli	Super Magnifier	Lookout Tower	Right-handed	Green Cap	Gummy Bears

Clue 1

Rounding

We check the digital footprints on the grass. The sensor screen only shows rounded estimates of the thief's weight.

Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.

300

130

2000

9000

110

5000

9000

1100

1700

500

130

2300

1100

500

300

5000

2000

130

300

130

5000

9000

900

110

500

3000

Round 20 to the nearest tenT

Round 325 to the nearest hundredH

Round 107 to the nearest tenL

Round 3,328 to the nearest thousandF

Round 2,336 to the nearest hundredS

Round 948 to the nearest hundredC

Round 128 to the nearest tenE

Round 1,720 to the nearest hundredD

Round 1,824 to the nearest thousandV

Round 545 to the nearest hundredO

Round 8,659 to the nearest thousandI

Round 1,089 to the nearest hundredN

Round 5,216 to the nearest thousandA

0/13 letters found

Clue 2

Addition

We gather all the dropped candy wrappers from the lawn. Let's count the total pile to see where they came from.

Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.

7079

6662

5344

7472

5460

8865

3604

4777

6979

7079

6470

4777

3395

7079

5344

6470

6979

7079

6662

7079

6662

5344

4777

6979

2834

6662

7079

6662

7881

4736

8419

4002 + 3077 =T

1743 + 1091 =G

3438 + 5427 =L

3239 + 1538 =R

2105 + 1499 =P

4130 + 4289 =D

1659 + 3685 =E

4010 + 2969 =I

2661 + 2075 =N

3428 + 3042 =W

3201 + 3461 =H

1081 + 2314 =O

3552 + 4329 =A

2395 + 5077 =C

3586 + 1874 =U

0/15 letters found

Clue 3

Subtraction

Some of our secret decoder cards are missing from the metal box. We subtract the remaining cards to find the stolen amount.

Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.

3363

7839

2651

4128

5831

1309

1435

7839

1285

4705

8482

6709

6331

5831

1285

6709

2411

7839

4227

2856

2411

4227

6331

3470

6680 - 3317 =W

6740 - 2035 =P

5985 - 1758 =A

4368 - 1512 =R

2336 - 1027 =N

10132 - 4301 =U

10018 - 1536 =T

6740 - 3270 =S

9699 - 2990 =Y

8819 - 4691 =O

3169 - 1734 =D

2377 - 1092 =M

6965 - 634 =G

4284 - 1873 =B

3670 - 1019 =F

9629 - 1790 =E

0/16 letters found

Clue 4

Multiplication facts (1-12)

The spy cameras are arranged in neat rows along the side fence. We multiply the rows and columns to find the total footage hours.

Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.

120

2 × 7 =W

12 × 10 =O

8 × 10 =F

2 × 11 =P

6 × 12 =H

12 × 5 =C

9 × 7 =N

10 × 2 =A

9 × 1 =U

6 × 11 =L

3 × 12 =E

8 × 11 =D

1 × 7 =T

4 × 10 =B

6 × 4 =R

0/15 letters found

Clue 5

Division facts (1-12) — the last clue

We must divide the key evidence cards equally among our detective teams so we can scan them faster.

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

18 ÷ 6 = ?

6 ÷ 1 = ?

63 ÷ 9 = ?

50 ÷ 10 = ?

8 ÷ 8 = ?

64 ÷ 8 = ?

12 ÷ 1 = ?

20 ÷ 10 = ?

110 ÷ 11 = ?

90 ÷ 10 = ?

99 ÷ 9 = ?

Step 2 — cross out the sentence with each answer

1.The villain listened closely through the door with a sound listener, then slipped out onto the back porch.

2.The villain examined the lock with a super magnifier, then climbed up to the lookout tower.

3.The villain listened closely through the door with a sound listener, then ducked inside the secret wardrobe.

4.The villain examined the lock with a super magnifier, then slid into the underground tunnel.

5.The villain used a grappling hook to scale the high wall, then slid into the underground tunnel.

6.The villain examined the lock with a super magnifier, then slipped out onto the back porch.

7.The villain shined a laser pointer to distract the guard dog, then climbed up to the lookout tower.

8.The villain used a grappling hook to scale the high wall, then hid in the attic loft.

9.The villain shined a laser pointer to distract the guard dog, then ducked inside the secret wardrobe.

10.The villain listened closely through the door with a sound listener, then climbed up to the lookout tower.

11.The villain listened closely through the door with a sound listener, then hid in the attic loft.

12.The villain crept in using night goggles, then hid in the attic loft.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Treehouse Spy Club: Case of the Missing Golden Pineapple

Culprit: Sophia (Super Magnifier · Underground Tunnel · Right-handed · Blue Cap · Gummy Bears)

Clue 1 (Rounding): "THE VILLAIN DOES NOT HAVE THE ATTIC LOFT"
Round 20 to the nearest ten = 20 (T) · Round 325 to the nearest hundred = 300 (H) · Round 107 to the nearest ten = 110 (L) · Round 3,328 to the nearest thousand = 3000 (F) · Round 2,336 to the nearest hundred = 2300 (S) · Round 948 to the nearest hundred = 900 (C) · Round 128 to the nearest ten = 130 (E) · Round 1,720 to the nearest hundred = 1700 (D) · Round 1,824 to the nearest thousand = 2000 (V) · Round 545 to the nearest hundred = 500 (O) · Round 8,659 to the nearest thousand = 9000 (I) · Round 1,089 to the nearest hundred = 1100 (N) · Round 5,216 to the nearest thousand = 5000 (A)
Clue 2 (Addition): "THE CULPRIT WROTE WITH THE RIGHT HAND"
4002 + 3077 = 7079 (T) · 1743 + 1091 = 2834 (G) · 3438 + 5427 = 8865 (L) · 3239 + 1538 = 4777 (R) · 2105 + 1499 = 3604 (P) · 4130 + 4289 = 8419 (D) · 1659 + 3685 = 5344 (E) · 4010 + 2969 = 6979 (I) · 2661 + 2075 = 4736 (N) · 3428 + 3042 = 6470 (W) · 3201 + 3461 = 6662 (H) · 1081 + 2314 = 3395 (O) · 3552 + 4329 = 7881 (A) · 2395 + 5077 = 7472 (C) · 3586 + 1874 = 5460 (U)
Clue 3 (Subtraction): "WE FOUND EMPTY GUMMY BEAR BAGS"
6680 - 3317 = 3363 (W) · 6740 - 2035 = 4705 (P) · 5985 - 1758 = 4227 (A) · 4368 - 1512 = 2856 (R) · 2336 - 1027 = 1309 (N) · 10132 - 4301 = 5831 (U) · 10018 - 1536 = 8482 (T) · 6740 - 3270 = 3470 (S) · 9699 - 2990 = 6709 (Y) · 8819 - 4691 = 4128 (O) · 3169 - 1734 = 1435 (D) · 2377 - 1092 = 1285 (M) · 6965 - 634 = 6331 (G) · 4284 - 1873 = 2411 (B) · 3670 - 1019 = 2651 (F) · 9629 - 1790 = 7839 (E)
Clue 4 (Multiplication facts (1-12)): "WE FOUND A BLUE CAP ON THE FLOOR"
2 × 7 = 14 (W) · 12 × 10 = 120 (O) · 8 × 10 = 80 (F) · 2 × 11 = 22 (P) · 6 × 12 = 72 (H) · 12 × 5 = 60 (C) · 9 × 7 = 63 (N) · 10 × 2 = 20 (A) · 9 × 1 = 9 (U) · 6 × 11 = 66 (L) · 3 × 12 = 36 (E) · 8 × 11 = 88 (D) · 1 × 7 = 7 (T) · 4 × 10 = 40 (B) · 6 × 4 = 24 (R)
Clue 5 (Division facts (1-12)): surviving statement (box 4) → Sophia
18 ÷ 6 = 3 · 6 ÷ 1 = 6 · 63 ÷ 9 = 7 · 50 ÷ 10 = 5 · 8 ÷ 8 = 1 · 64 ÷ 8 = 8 · 12 ÷ 1 = 12 · 20 ÷ 10 = 2 · 110 ÷ 11 = 10 · 90 ÷ 10 = 9 · 99 ÷ 9 = 11

About this mystery

Grade level: Grade 4 math
Math topics: Rounding, Addition, Subtraction, Multiplication, Division
Reading level: grades 3-4
Theme: The Treehouse Spy Club: Case of the Missing Golden Pineapple — set in The Treehouse Club Cabin
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

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