🌊 MermaidsGrade 6Reading: grades 3-4AdditionSubtractionMultiplicationFractions of a numberDivision
The Coral Cove Mystery
Someone swiped the Golden Sea Pearl from the Royal Reef Vault! Help the Ocean Patrol decode the evidence and catch the sneaky 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 | Ocean Gear | Handedness | Fin Color | Weakness |
|---|---|---|---|---|---|
| Ariel | Dolphin Talk | Coral Trident | Right Handed | Emerald Green | Ticklish Fins |
| Bubbles | Bioluminescence | Starfish Compass | Left Handed | Ruby Pink | Bright Lights |
| Kelp | Bioluminescence | Coral Trident | Left Handed | Emerald Green | Loud Conch Calls |
| Delphine | Dolphin Talk | Starfish Compass | Left Handed | Ruby Pink | Bright Lights |
| Shelly | Tide Control | Coral Trident | Right Handed | Emerald Green | Loud Conch Calls |
| Pearl | Whirlpool Spin | Shell Shield | Left Handed | Sapphire Blue | Ticklish Fins |
| Finn | Bioluminescence | Kelp Lasso | Right Handed | Sapphire Blue | Bright Lights |
| Wave | Bioluminescence | Pearl Crown | Left Handed | Emerald Green | Bright Lights |
| Triton | Dolphin Talk | Shell Shield | Left Handed | Emerald Green | Bright Lights |
| Caspian | Bioluminescence | Kelp Lasso | Left Handed | Ruby Pink | Ticklish Fins |
| Calypso | Bioluminescence | Kelp Lasso | Right Handed | Ruby Pink | Ticklish Fins |
| Sandy | Dolphin Talk | Shell Shield | Right Handed | Sapphire Blue | Bright Lights |
| Ray | Whirlpool Spin | Pearl Crown | Right Handed | Ruby Pink | Ticklish Fins |
| Nautilus | Tide Control | Kelp Lasso | Left Handed | Ruby Pink | Ticklish Fins |
| Cascade | Dolphin Talk | Kelp Lasso | Left Handed | Ruby Pink | Bright Lights |
| Mako | Current Glide | Shell Shield | Left Handed | Emerald Green | Bright Lights |
| Nereus | Bioluminescence | Pearl Crown | Right Handed | Sapphire Blue | Ticklish Fins |
| Coralia | Bioluminescence | Coral Trident | Left Handed | Emerald Green | Bright Lights |
| Briny | Tide Control | Coral Trident | Right Handed | Ruby Pink | Bright Lights |
| Scylla | Dolphin Talk | Coral Trident | Left Handed | Emerald Green | Bright Lights |
| Marina | Tide Control | Coral Trident | Right Handed | Emerald Green | Bright Lights |
Clue 1
Addition
Guard dolphins tallied all the missing sea sponges around the vault to find 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
9850
7151
8491
4583
4005
8491
8701
9032
2998
T
9850
7151
3062
8491
2650
5475
6069
8491
4583
4005
6069
T
9850
5633
8491
8701
3900
8701
3776
8491
8701
3900
3536
4760
3900
6069
5633
4005
5427 + 4423 =T
2409 + 1367 =P
5497 + 3535 =K
2224 + 1312 =L
5401 + 3090 =E
2107 + 955 =I
2639 + 2836 =D
3583 + 2486 =O
1814 + 2086 =R
1528 + 3055 =S
3471 + 2162 =W
1503 + 3257 =C
1129 + 1521 =F
1299 + 1699 =Y
2724 + 1281 =N
4702 + 2449 =H
5382 + 3319 =A
0/17 letters found
Clue 2
Subtraction
The patrol subtracted damaged coral reefs from the safe ones to narrow down the path.
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
2675
6424
3823
1193
3967
4262
4262
4262
2947
W
2675
2947
1896
3967
2745
3823
2413
2947
1193
7468
3967
7468
8764
3967
1958
8764
2947
6424
7468
2745
1896
3967
3967
5490 - 2815 =W
11718 - 2954 =M
4028 - 2132 =L
9086 - 1618 =D
3529 - 784 =F
5771 - 2824 =A
6376 - 4418 =R
5436 - 1613 =T
2447 - 34 =H
11155 - 4731 =I
1454 - 261 =N
7059 - 3092 =E
5962 - 1700 =S
0/13 letters found
Clue 3
Multiplication facts (1-12)
Ocean scouts counted rows of giant clam shells to find a hidden secret message.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
G
2
30
36
18
64
99
G
2
54
27
30
30
81
66
64
77
63
77
40
8
80
27
49
110
63
27
110
63
64
27
66
2 × 1 =G
9 × 9 =Y
6 × 11 =F
6 × 5 =L
10 × 11 =T
3 × 6 =W
3 × 9 =E
8 × 8 =I
3 × 12 =O
8 × 1 =A
10 × 4 =C
8 × 10 =R
9 × 11 =N
6 × 9 =J
7 × 7 =D
9 × 7 =H
11 × 7 =S
0/17 letters found
Clue 4
Fractions of a number
The royal tidekeeper calculated a fraction of the shining pearls left in the chest.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
G
14
34
4
4
27
32
10
5
30
4
32
40
4
34
4
22
34
3
23
23
4
22
5
31
31
16
4
32
10
4
27
4
2/3 of 21 =G
5/6 of 6 =A
2/10 of 50 =C
1/5 of 80 =H
1/4 of 12 =O
1/6 of 24 =E
1/2 of 44 =D
1/4 of 160 =W
2/8 of 108 =N
3/4 of 40 =L
1/6 of 138 =P
4/6 of 51 =R
2/6 of 96 =S
5/10 of 62 =T
0/14 letters found
Clue 5
Division facts (1-12) — the last clue
The kelp guards divided the deep sea sectors evenly to locate 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
32 ÷ 8 = ?
56 ÷ 7 = ?
42 ÷ 7 = ?
84 ÷ 12 = ?
36 ÷ 12 = ?
54 ÷ 6 = ?
35 ÷ 7 = ?
8 ÷ 4 = ?
110 ÷ 10 = ?
10 ÷ 10 = ?
80 ÷ 8 = ?
Step 2 — cross out the sentence with each answer
1.The villain surged ahead on swift currents, then snagged the pearl using a kelp lasso.
2.The villain summoned a giant whirlpool, then slashed the vault ropes with a coral trident.
3.The villain lit up the dark ocean cave, then navigated the maze with a starfish compass.
4.The villain spoke to the guard dolphins, then slashed the vault ropes with a coral trident.
5.The villain bent the tidal waters, then blocked the sea guards with a shell shield.
6.The villain lit up the dark ocean cave, then slashed the vault ropes with a coral trident.
7.The villain bent the tidal waters, then navigated the maze with a starfish compass.
8.The villain spoke to the guard dolphins, then blocked the sea guards with a shell shield.
9.The villain lit up the dark ocean cave, then blocked the sea guards with a shell shield.
10.The villain spoke to the guard dolphins, then snagged the pearl using a kelp lasso.
11.The villain spoke to the guard dolphins, then navigated the maze with a starfish compass.
12.The villain surged ahead on swift currents, then blocked the sea guards with a shell shield.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Coral Cove Mystery
Culprit: Mako (Current Glide · Shell Shield · Left Handed · Emerald Green · Bright Lights)
- Clue 1 (Addition): "THE SNEAKY THIEF DOES NOT WEAR A PEARL CROWN"5427 + 4423 = 9850 (T) · 2409 + 1367 = 3776 (P) · 5497 + 3535 = 9032 (K) · 2224 + 1312 = 3536 (L) · 5401 + 3090 = 8491 (E) · 2107 + 955 = 3062 (I) · 2639 + 2836 = 5475 (D) · 3583 + 2486 = 6069 (O) · 1814 + 2086 = 3900 (R) · 1528 + 3055 = 4583 (S) · 3471 + 2162 = 5633 (W) · 1503 + 3257 = 4760 (C) · 1129 + 1521 = 2650 (F) · 1299 + 1699 = 2998 (Y) · 2724 + 1281 = 4005 (N) · 4702 + 2449 = 7151 (H) · 5382 + 3319 = 8701 (A)
- Clue 2 (Subtraction): "WITNESS SAW A LEFT HANDED MERMAID FLEE"5490 - 2815 = 2675 (W) · 11718 - 2954 = 8764 (M) · 4028 - 2132 = 1896 (L) · 9086 - 1618 = 7468 (D) · 3529 - 784 = 2745 (F) · 5771 - 2824 = 2947 (A) · 6376 - 4418 = 1958 (R) · 5436 - 1613 = 3823 (T) · 2447 - 34 = 2413 (H) · 11155 - 4731 = 6424 (I) · 1454 - 261 = 1193 (N) · 7059 - 3092 = 3967 (E) · 5962 - 1700 = 4262 (S)
- Clue 3 (Multiplication facts (1-12)): "GLOWING JELLYFISH SCARED THE THIEF"2 × 1 = 2 (G) · 9 × 9 = 81 (Y) · 6 × 11 = 66 (F) · 6 × 5 = 30 (L) · 10 × 11 = 110 (T) · 3 × 6 = 18 (W) · 3 × 9 = 27 (E) · 8 × 8 = 64 (I) · 3 × 12 = 36 (O) · 8 × 1 = 8 (A) · 10 × 4 = 40 (C) · 8 × 10 = 80 (R) · 9 × 11 = 99 (N) · 6 × 9 = 54 (J) · 7 × 7 = 49 (D) · 9 × 7 = 63 (H) · 11 × 7 = 77 (S)
- Clue 4 (Fractions of a number): "GREEN SCALES WERE DROPPED AT THE SCENE"2/3 of 21 = 14 (G) · 5/6 of 6 = 5 (A) · 2/10 of 50 = 10 (C) · 1/5 of 80 = 16 (H) · 1/4 of 12 = 3 (O) · 1/6 of 24 = 4 (E) · 1/2 of 44 = 22 (D) · 1/4 of 160 = 40 (W) · 2/8 of 108 = 27 (N) · 3/4 of 40 = 30 (L) · 1/6 of 138 = 23 (P) · 4/6 of 51 = 34 (R) · 2/6 of 96 = 32 (S) · 5/10 of 62 = 31 (T)
- Clue 5 (Division facts (1-12)): surviving statement (box 12) → Mako32 ÷ 8 = 4 · 56 ÷ 7 = 8 · 42 ÷ 7 = 6 · 84 ÷ 12 = 7 · 36 ÷ 12 = 3 · 54 ÷ 6 = 9 · 35 ÷ 7 = 5 · 8 ÷ 4 = 2 · 110 ÷ 10 = 11 · 10 ÷ 10 = 1 · 80 ÷ 8 = 10
About this mystery
- Grade level
- Grade 6 math
- Math topics
- Addition, Subtraction, Multiplication, Fractions of a number, Division
- Reading level
- grades 3-4
- Theme
- The Coral Cove Mystery — set in Coral Cove Reef Palace
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects