🌊 MermaidsGrade 5Reading: grades 5-6MultiplicationRoundingWord problemsFractions of a numberDivision
The Case of the Missing Pearl Scepter
Queen Coralia woke up to find the Pearl Scepter missing from the Reef Palace vaults. A rogue sea sorcerer snuck inside, leaving ocean clues behind. Use your detective skills and marine evidence to unmask the aquatic thief.
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 | Sea Magic | Enchanted Relic | Swimming Style | Tail Fins | Magic Shell |
|---|---|---|---|---|---|
| Coralia Reef | Bubble Blasting | Conch Horn | Left Fins Swimmer | Deep Emerald Fin | Sunlit Amber Shell |
| Pearl Periwinkle | Whirlpool Summoning | Pearl Shield | Right Fins Swimmer | Iridescent Pink Fin | Prismatic Opal Shell |
| Oceana Crest | Tide Bending | Conch Horn | Right Fins Swimmer | Deep Emerald Fin | Prismatic Opal Shell |
| Triton Sands | Coral Sculpting | Pearl Shield | Right Fins Swimmer | Deep Emerald Fin | Sunlit Amber Shell |
| Delphine Tide | Siren Chanting | Conch Horn | Left Fins Swimmer | Deep Emerald Fin | Sonic Conch Shell |
| Calypso Cove | Bubble Blasting | Pearl Shield | Left Fins Swimmer | Iridescent Pink Fin | Sonic Conch Shell |
| Glaucus Foam | Tide Bending | Conch Horn | Left Fins Swimmer | Deep Emerald Fin | Prismatic Opal Shell |
| Marina Wave | Coral Sculpting | Pearl Shield | Left Fins Swimmer | Iridescent Pink Fin | Sunlit Amber Shell |
| Caspian Shell | Bubble Blasting | Conch Horn | Left Fins Swimmer | Deep Emerald Fin | Prismatic Opal Shell |
| Doris Trench | Coral Sculpting | Glow Lantern | Left Fins Swimmer | Shimmering Turquoise Fin | Prismatic Opal Shell |
| Ray Surge | Bubble Blasting | Glow Lantern | Left Fins Swimmer | Deep Emerald Fin | Sunlit Amber Shell |
| Vapor Eddy | Siren Chanting | Conch Horn | Left Fins Swimmer | Deep Emerald Fin | Sunlit Amber Shell |
| Nautilus Ned | Tide Bending | Pearl Shield | Left Fins Swimmer | Shimmering Turquoise Fin | Prismatic Opal Shell |
| Maren Deep | Coral Sculpting | Trident Flash | Left Fins Swimmer | Deep Emerald Fin | Sunlit Amber Shell |
| Nereus Splash | Bubble Blasting | Kelp Lasso | Right Fins Swimmer | Deep Emerald Fin | Sunlit Amber Shell |
| Tethys Brook | Coral Sculpting | Pearl Shield | Left Fins Swimmer | Shimmering Turquoise Fin | Prismatic Opal Shell |
| Pelagia Spray | Bubble Blasting | Kelp Lasso | Left Fins Swimmer | Deep Emerald Fin | Sunlit Amber Shell |
| Kai Current | Tide Bending | Glow Lantern | Left Fins Swimmer | Iridescent Pink Fin | Sonic Conch Shell |
| Thalassa Shoal | Whirlpool Summoning | Conch Horn | Left Fins Swimmer | Iridescent Pink Fin | Prismatic Opal Shell |
| Nerida Salt | Siren Chanting | Glow Lantern | Right Fins Swimmer | Iridescent Pink Fin | Sunlit Amber Shell |
| Sirenna Blue | Bubble Blasting | Kelp Lasso | Left Fins Swimmer | Deep Emerald Fin | Prismatic Opal Shell |
Clue 1
Multiplication facts (1-12)
The guard calculated the total number of magic clams in grid rows to decrypt the first 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.
T
55
77
132
44
45
50
50
3
45
9
84
45
84
9
100
T
55
6
3
8
8
80
3
28
50
100
14
50
3
9
T
55
132
8
9
11 × 5 =T
3 × 2 =C
4 × 2 =R
11 × 7 =H
2 × 7 =W
1 × 9 =N
10 × 10 =O
11 × 12 =E
12 × 7 =D
9 × 5 =I
5 × 10 =L
4 × 11 =V
7 × 4 =G
8 × 10 =Y
3 × 1 =A
0/15 letters found
Clue 2
Rounding
The sonar console rounded the depth readings to the nearest hundred meters to reveal ocean movements.
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
700
300
900
130
3700
130
1300
900
200
T
700
130
110
9000
1700
300
9000
20
290
T
700
2300
110
9000
20
290
T
700
300
900
2000
900
170
T
700
170
2000
9000
90
500
Round 699 to the nearest hundredT
Round 106 to the nearest tenW
Round 267 to the nearest hundredH
Round 1,268 to the nearest hundredP
Round 3,699 to the nearest hundredU
Round 171 to the nearest tenF
Round 8,550 to the nearest thousandA
Round 290 to the nearest tenD
Round 2,309 to the nearest thousandL
Round 538 to the nearest hundredK
Round 17 to the nearest tenR
Round 908 to the nearest hundredE
Round 1,701 to the nearest hundredM
Round 90 to the nearest tenN
Round 127 to the nearest tenS
Round 2,266 to the nearest hundredO
Round 190 to the nearest hundredC
0/17 letters found
Clue 3
Word problems
Analyzing the supply logs of sea crystal crates gives us the next clue.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Someonescaredthevillainoffwith .
S
112
63
43
12
58
82
103
M
B
E
R
S
112
H
E
12
12
There were 124 starfish tokens. 12 were used up. How many starfish tokens are left?S
Reef Scout lined up 7 rows of 9 sea shells. How many sea shells in all?U
Reef Scout found 10 starfish tokens yesterday and 2 more today. How many starfish tokens in all?L
There were 67 starfish tokens. 24 were used up. How many starfish tokens are left?N
There were 143 glowing pearls. 40 were used up. How many glowing pearls are left?A
There were 121 kelp bundles. 39 were used up. How many kelp bundles are left?T
Reef Scout found 30 coral gems yesterday and 28 more today. How many coral gems in all?I
0/7 letters found
Clue 4
Fractions of a number
The vault code requires taking a precise fraction of the total pearl count stored inside.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
E
27
39
E
27
14
15
3
31
26
17
8
10
4
15
3
E
27
10
5
E
27
14
E
27
31
14
6
32
32
E
27
31
15
13
13
25
E
27
30
15
13
E
27
1/3 of 81 =E
4/6 of 48 =P
1/10 of 150 =A
5/10 of 16 =N
2/8 of 56 =R
5/6 of 6 =W
3/8 of 16 =O
1/5 of 65 =T
5/8 of 40 =H
3/4 of 4 =L
1/4 of 104 =F
1/4 of 156 =M
2/10 of 50 =S
1/3 of 12 =C
1/2 of 60 =G
1/4 of 68 =I
4/8 of 62 =D
0/17 letters found
Clue 5
Division facts (1-12) — the last clue
Dividing the salvaged gold doubloons equally among five patrol guards unlocks the final lead.
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
12 ÷ 12 = ?
50 ÷ 10 = ?
56 ÷ 8 = ?
30 ÷ 3 = ?
4 ÷ 1 = ?
18 ÷ 2 = ?
4 ÷ 2 = ?
96 ÷ 12 = ?
72 ÷ 6 = ?
18 ÷ 6 = ?
18 ÷ 3 = ?
Step 2 — cross out the sentence with each answer
1.The villain blasted heavy bubbles, then threw a kelp lasso.
2.The villain sculpted sharp coral, then raised a pearl shield.
3.The villain summoned a wild whirlpool, then lit a glow lantern.
4.The villain summoned a wild whirlpool, then threw a kelp lasso.
5.The villain sang a siren chant, then blew a conch horn.
6.The villain bent the ocean tides, then lit a glow lantern.
7.The villain sculpted sharp coral, then flashed a sea trident.
8.The villain summoned a wild whirlpool, then blew a conch horn.
9.The villain sang a siren chant, then flashed a sea trident.
10.The villain sculpted sharp coral, then lit a glow lantern.
11.The villain blasted heavy bubbles, then blew a conch horn.
12.The villain summoned a wild whirlpool, then flashed a sea trident.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Case of the Missing Pearl Scepter
Culprit: Coralia Reef (Bubble Blasting · Conch Horn · Left Fins Swimmer · Deep Emerald Fin · Sunlit Amber Shell)
- Clue 1 (Multiplication facts (1-12)): "THE VILLAIN DID NOT CARRY A GLOW LANTERN"11 × 5 = 55 (T) · 3 × 2 = 6 (C) · 4 × 2 = 8 (R) · 11 × 7 = 77 (H) · 2 × 7 = 14 (W) · 1 × 9 = 9 (N) · 10 × 10 = 100 (O) · 11 × 12 = 132 (E) · 12 × 7 = 84 (D) · 9 × 5 = 45 (I) · 5 × 10 = 50 (L) · 4 × 11 = 44 (V) · 7 × 4 = 28 (G) · 8 × 10 = 80 (Y) · 3 × 1 = 3 (A)
- Clue 2 (Rounding): "THE SUSPECT SWAM HARD TOWARD THE LEFT FLANK"Round 699 to the nearest hundred = 700 (T) · Round 106 to the nearest ten = 110 (W) · Round 267 to the nearest hundred = 300 (H) · Round 1,268 to the nearest hundred = 1300 (P) · Round 3,699 to the nearest hundred = 3700 (U) · Round 171 to the nearest ten = 170 (F) · Round 8,550 to the nearest thousand = 9000 (A) · Round 290 to the nearest ten = 290 (D) · Round 2,309 to the nearest thousand = 2000 (L) · Round 538 to the nearest hundred = 500 (K) · Round 17 to the nearest ten = 20 (R) · Round 908 to the nearest hundred = 900 (E) · Round 1,701 to the nearest hundred = 1700 (M) · Round 90 to the nearest ten = 90 (N) · Round 127 to the nearest ten = 130 (S) · Round 2,266 to the nearest hundred = 2300 (O) · Round 190 to the nearest hundred = 200 (C)
- Clue 3 (Word problems): "SUNLIT AMBER SHELL"There were 124 starfish tokens. 12 were used up. How many starfish tokens are left? = 112 (S) · Reef Scout lined up 7 rows of 9 sea shells. How many sea shells in all? = 63 (U) · Reef Scout found 10 starfish tokens yesterday and 2 more today. How many starfish tokens in all? = 12 (L) · There were 67 starfish tokens. 24 were used up. How many starfish tokens are left? = 43 (N) · There were 143 glowing pearls. 40 were used up. How many glowing pearls are left? = 103 (A) · There were 121 kelp bundles. 39 were used up. How many kelp bundles are left? = 82 (T) · Reef Scout found 30 coral gems yesterday and 28 more today. How many coral gems in all? = 58 (I)
- Clue 4 (Fractions of a number): "EMERALD FIN SCALES WERE DROPPED AT THE GATE"1/3 of 81 = 27 (E) · 4/6 of 48 = 32 (P) · 1/10 of 150 = 15 (A) · 5/10 of 16 = 8 (N) · 2/8 of 56 = 14 (R) · 5/6 of 6 = 5 (W) · 3/8 of 16 = 6 (O) · 1/5 of 65 = 13 (T) · 5/8 of 40 = 25 (H) · 3/4 of 4 = 3 (L) · 1/4 of 104 = 26 (F) · 1/4 of 156 = 39 (M) · 2/10 of 50 = 10 (S) · 1/3 of 12 = 4 (C) · 1/2 of 60 = 30 (G) · 1/4 of 68 = 17 (I) · 4/8 of 62 = 31 (D)
- Clue 5 (Division facts (1-12)): surviving statement (box 11) → Coralia Reef12 ÷ 12 = 1 · 50 ÷ 10 = 5 · 56 ÷ 8 = 7 · 30 ÷ 3 = 10 · 4 ÷ 1 = 4 · 18 ÷ 2 = 9 · 4 ÷ 2 = 2 · 96 ÷ 12 = 8 · 72 ÷ 6 = 12 · 18 ÷ 6 = 3 · 18 ÷ 3 = 6
About this mystery
- Grade level
- Grade 5 math
- Math topics
- Multiplication, Rounding, Word problems, Fractions of a number, Division
- Reading level
- grades 5-6
- Theme
- The Case of the Missing Pearl Scepter — set in Coral Lagoon Reef Palace
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects