Grade 4Reading: grades 3-4Fractions of a numberRoundingAdditionSubtraction

The Cloud Island Caper

The Golden Compass Rose has vanished from the Grand Zephyr airship! The Chief Cartographer needs your help to track down the sneaky rogue explorer who took it before they escape to the high cloud islands.

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	Gear Used	Ranger Badge	Writing Hand	Hair Color	Dropped Snack
Zoe	grapple boots	star badge	writes with left hand	blond hair	coconut drops
Kip	grapple boots	star badge	writes with right hand	brown hair	maple fudge
Kai	grapple hook	wind badge	writes with right hand	blond hair	banana chips
Mac	zip-line gloves	star badge	writes with left hand	blond hair	coconut drops
Mia	glider pack	star badge	writes with left hand	blond hair	banana chips
Ted	grapple boots	sun badge	writes with left hand	brown hair	maple fudge
Amy	grapple hook	cloud badge	writes with right hand	black hair	maple fudge
Rex	zip-line gloves	storm badge	writes with left hand	blond hair	coconut drops
Sid	grapple hook	sun badge	writes with right hand	blond hair	banana chips
Roy	grapple hook	wind badge	writes with left hand	blond hair	coconut drops
Maya	smoke bomb	cloud badge	writes with left hand	black hair	coconut drops
Ben	grapple hook	wind badge	writes with left hand	blond hair	banana chips
Dan	glider pack	star badge	writes with right hand	blond hair	maple fudge
Max	grapple boots	star badge	writes with left hand	black hair	coconut drops
Joy	grapple boots	sun badge	writes with left hand	brown hair	banana chips
Ned	zip-line gloves	cloud badge	writes with left hand	black hair	maple fudge
Kit	zip-line gloves	storm badge	writes with left hand	blond hair	banana chips
Cal	smoke bomb	star badge	writes with right hand	black hair	banana chips
Leo	zip-line gloves	sun badge	writes with right hand	blond hair	banana chips
Jax	grapple hook	storm badge	writes with right hand	blond hair	coconut drops
Sam	grapple hook	sun badge	writes with left hand	blond hair	coconut drops

Clue 1

Fractions of a number

The airship crew found a crate of cargo. Some of the boxes are missing. We need to find the fraction of the remaining boxes to unlock the first cabin door.

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

1/5 of 15 =T

2/4 of 76 =N

1/4 of 136 =W

1/8 of 96 =A

5/10 of 8 =V

1/3 of 57 =H

1/8 of 88 =O

1/10 of 80 =E

1/4 of 148 =B

1/5 of 35 =G

2/6 of 99 =S

4/6 of 21 =D

4/8 of 46 =F

1/4 of 124 =I

0/14 letters found

Clue 2

Rounding

The airship altimeter is acting up on our climb. The dial only shows the altitude rounded to the nearest ten. Round these numbers to read the next clue.

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

4300

200

7000

3000

290

230

200

290

230

4300

230

700

500

4300

2300

110

1700

Round 46 to the nearest tenT

Round 74 to the nearest tenU

Round 3,177 to the nearest thousandC

Round 1,732 to the nearest hundredD

Round 4,276 to the nearest hundredH

Round 2,284 to the nearest hundredA

Round 227 to the nearest tenI

Round 154 to the nearest hundredS

Round 89 to the nearest tenR

Round 110 to the nearest tenN

Round 7,120 to the nearest thousandP

Round 286 to the nearest tenW

Round 23 to the nearest tenE

Round 702 to the nearest hundredL

Round 461 to the nearest hundredF

0/15 letters found

Clue 3

Addition

We found a pile of dropped copper gears on the deck. Add the gear counts together to see how many the thief lost.

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

8511

4566

6324

6547

6677

6971

2942

5696

6324

6677

8715

3596

8511

9675

6988

3225

6547

6988

2942

6988

2942

8275

2880

8511

6677

6971

2942

5696

4684 + 3827 =T

2918 + 3406 =E

3807 + 2870 =D

2166 + 2400 =H

1499 + 1381 =U

2781 + 4207 =C

2118 + 4853 =R

6082 + 3593 =I

1329 + 1896 =K

1926 + 3770 =P

2118 + 1478 =S

5227 + 3488 =A

1247 + 1695 =O

2080 + 4467 =Y

4430 + 3845 =N

0/15 letters found

Clue 4

Subtraction

The escape glider used up some of its fuel tanks. Subtract the empty tanks from the starting total to see how much fuel remains.

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

7075

2160

8964

8385

2695

1185

6225

5364

2615

7036

6213

1185

6225

5364

8385

8964

5364

5330

3621

1185

2625

4080

4096

8385

1185

6225

5330

6213

3621

7036

10393 - 3318 =W

7194 - 4569 =Y

7328 - 4713 =T

9363 - 3999 =S

11940 - 4904 =R

9506 - 1121 =O

1888 - 703 =N

7115 - 890 =D

9090 - 2877 =A

6356 - 2276 =B

9004 - 40 =F

7128 - 4968 =E

4503 - 407 =L

6211 - 881 =H

8012 - 4391 =I

5135 - 2440 =U

0/16 letters found

Clue 5

Fractions of a number — the last clue

Our scout found a pouch of shiny island crystals left behind. Work out the fraction of the blue crystals to find the final hideout.

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

1/5 of 50 = ?

6/8 of 4 = ?

1/8 of 88 = ?

3/5 of 20 = ?

3/6 of 2 = ?

1/5 of 20 = ?

2/4 of 16 = ?

5/6 of 6 = ?

2/5 of 15 = ?

1/8 of 56 = ?

2/4 of 4 = ?

Step 2 — cross out the sentence with each answer

1.The villain swings across the clouds on a rope, then snatches a map of the floating reefs.

2.The villain escapes through a secret trapdoor, then accidentally triggers the storm alarm.

3.The villain darts behind a giant steam pipe, then knocks over a stack of empty crates.

4.The villain darts behind a giant steam pipe, then accidentally triggers the storm alarm.

5.The villain slides down the anchor line, then snatches a map of the floating reefs.

6.The villain swings across the clouds on a rope, then drops a trail of glittery sky dust.

7.The villain slides down the anchor line, then knocks over a stack of empty crates.

8.The villain zooms away on a rusty glider, then drops a trail of glittery sky dust.

9.The villain darts behind a giant steam pipe, then leaves behind a muddy boot print.

10.The villain swings across the clouds on a rope, then accidentally triggers the storm alarm.

11.The villain slides down the anchor line, then leaves behind a muddy boot print.

12.The villain zooms away on a rusty glider, then knocks over a stack of empty crates.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Cloud Island Caper

Culprit: Mac (zip-line gloves · star badge · writes with left hand · blond hair · coconut drops)

Clue 1 (Fractions of a number): "THE THIEF DOES NOT HAVE THE WIND BADGE"
1/5 of 15 = 3 (T) · 2/4 of 76 = 38 (N) · 1/4 of 136 = 34 (W) · 1/8 of 96 = 12 (A) · 5/10 of 8 = 4 (V) · 1/3 of 57 = 19 (H) · 1/8 of 88 = 11 (O) · 1/10 of 80 = 8 (E) · 1/4 of 148 = 37 (B) · 1/5 of 35 = 7 (G) · 2/6 of 99 = 33 (S) · 4/6 of 21 = 14 (D) · 4/8 of 46 = 23 (F) · 1/4 of 124 = 31 (I)
Clue 2 (Rounding): "THE SUSPECT WRITES WITH THEIR LEFT HAND"
Round 46 to the nearest ten = 50 (T) · Round 74 to the nearest ten = 70 (U) · Round 3,177 to the nearest thousand = 3000 (C) · Round 1,732 to the nearest hundred = 1700 (D) · Round 4,276 to the nearest hundred = 4300 (H) · Round 2,284 to the nearest hundred = 2300 (A) · Round 227 to the nearest ten = 230 (I) · Round 154 to the nearest hundred = 200 (S) · Round 89 to the nearest ten = 90 (R) · Round 110 to the nearest ten = 110 (N) · Round 7,120 to the nearest thousand = 7000 (P) · Round 286 to the nearest ten = 290 (W) · Round 23 to the nearest ten = 20 (E) · Round 702 to the nearest hundred = 700 (L) · Round 461 to the nearest hundred = 500 (F)
Clue 3 (Addition): "THEY DROPPED A STICKY COCONUT DROP"
4684 + 3827 = 8511 (T) · 2918 + 3406 = 6324 (E) · 3807 + 2870 = 6677 (D) · 2166 + 2400 = 4566 (H) · 1499 + 1381 = 2880 (U) · 2781 + 4207 = 6988 (C) · 2118 + 4853 = 6971 (R) · 6082 + 3593 = 9675 (I) · 1329 + 1896 = 3225 (K) · 1926 + 3770 = 5696 (P) · 2118 + 1478 = 3596 (S) · 5227 + 3488 = 8715 (A) · 1247 + 1695 = 2942 (O) · 2080 + 4467 = 6547 (Y) · 4430 + 3845 = 8275 (N)
Clue 4 (Subtraction): "WE FOUND STRANDS OF SHINY BLOND HAIR"
10393 - 3318 = 7075 (W) · 7194 - 4569 = 2625 (Y) · 7328 - 4713 = 2615 (T) · 9363 - 3999 = 5364 (S) · 11940 - 4904 = 7036 (R) · 9506 - 1121 = 8385 (O) · 1888 - 703 = 1185 (N) · 7115 - 890 = 6225 (D) · 9090 - 2877 = 6213 (A) · 6356 - 2276 = 4080 (B) · 9004 - 40 = 8964 (F) · 7128 - 4968 = 2160 (E) · 4503 - 407 = 4096 (L) · 6211 - 881 = 5330 (H) · 8012 - 4391 = 3621 (I) · 5135 - 2440 = 2695 (U)
Clue 5 (Fractions of a number): surviving statement (box 9) → Mac
1/5 of 50 = 10 · 6/8 of 4 = 3 · 1/8 of 88 = 11 · 3/5 of 20 = 12 · 3/6 of 2 = 1 · 1/5 of 20 = 4 · 2/4 of 16 = 8 · 5/6 of 6 = 5 · 2/5 of 15 = 6 · 1/8 of 56 = 7 · 2/4 of 4 = 2

About this mystery

Grade level: Grade 4 math
Math topics: Fractions of a number, Rounding, Addition, Subtraction
Reading level: grades 3-4
Theme: The Cloud Island Caper — set in the floating docks of Zephyr Bay
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

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