🌊 MermaidsGrade 4Reading: grades 5-6AdditionPlace valueWord problemsBar modelsDivision
The Coral Cavern Pearl Heist
A glowing royal pearl has vanished from the Grand Shell Vault in Coral City. The culprit left behind clues throughout the underwater kingdom.
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 Ability | Relic Tool | Dominant Fin | Tail Streak Color | Unusual Weakness |
|---|---|---|---|---|---|
| Gale Floods | Tide Shield | Sea Glass Wand | Right Fin Striker | Seafoam Green | Dry Sand |
| Cora Trench | Siren Song | Kelp Whip | Right Fin Striker | Seafoam Green | Fresh Water |
| Dory Splashes | Tide Shield | Anchor Charm | Left Fin Striker | Seafoam Green | Dry Sand |
| Siren Sands | Siren Song | Shell Whistle | Left Fin Striker | Kelp Blue | Dry Sand |
| Pearl Shell | Siren Song | Pearl Staff | Left Fin Striker | Seafoam Green | Dry Sand |
| Oceanus Crest | Wave Control | Shell Whistle | Left Fin Striker | Kelp Blue | Dry Sand |
| Maris Shoal | Bubble Blast | Kelp Whip | Right Fin Striker | Seafoam Green | Dry Sand |
| Finn Triton | Coral Shape | Kelp Whip | Right Fin Striker | Seafoam Green | Flashlight Beam |
| Thalassa Surge | Coral Shape | Sea Glass Wand | Right Fin Striker | Kelp Blue | Flashlight Beam |
| Marina Aqua | Siren Song | Kelp Whip | Left Fin Striker | Seafoam Green | Dry Sand |
| Mako Shark | Siren Song | Pearl Staff | Left Fin Striker | Coral Pink | Dry Sand |
| Nerida Waves | Coral Shape | Sea Glass Wand | Right Fin Striker | Coral Pink | Fresh Water |
| Nixie Reef | Tide Shield | Pearl Staff | Left Fin Striker | Seafoam Green | Dry Sand |
| Kelp Mariner | Tide Shield | Sea Glass Wand | Right Fin Striker | Seafoam Green | Flashlight Beam |
| Tide Current | Wave Control | Kelp Whip | Left Fin Striker | Kelp Blue | Flashlight Beam |
| Abyssal Ray | Wave Control | Sea Glass Wand | Left Fin Striker | Seafoam Green | Dry Sand |
| Nautica Blue | Siren Song | Anchor Charm | Left Fin Striker | Kelp Blue | Dry Sand |
| Coralia Deep | Tide Shield | Pearl Staff | Left Fin Striker | Coral Pink | Flashlight Beam |
| Cascada Spray | Bubble Blast | Shell Whistle | Left Fin Striker | Kelp Blue | Dry Sand |
| Breeze Waters | Siren Song | Shell Whistle | Right Fin Striker | Kelp Blue | Dry Sand |
| Shelly Beach | Coral Shape | Anchor Charm | Left Fin Striker | Seafoam Green | Flashlight Beam |
Clue 1
Addition
Guard Captain Reef adds up the collected shell tokens to track the bandit's 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.
T
4594
3575
9626
5847
9686
9815
9088
3038
T
4594
9088
9652
9626
9836
9815
9652
T
4594
2123
9836
9626
9686
3365
9626
7240
9402
9759
3575
3038
9402
2130 + 2464 =T
2472 + 4768 =L
1964 + 1401 =K
6353 + 3406 =W
6154 + 3472 =E
4596 + 5219 =N
4062 + 5026 =D
1198 + 925 =U
4577 + 4825 =P
5825 + 3861 =A
5462 + 4374 =S
2980 + 6672 =O
1640 + 1935 =H
3916 + 1931 =B
1798 + 1240 =I
0/15 letters found
Clue 2
Place value
Analyzing the vault lock digit positions reveals a hidden place value code.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
A
200
3000
30
1000
10
70
600
600
600
A
200
3000
A
200
7000
70
800
1000
800
30
10
600
1000
50
30
5000
70
50
800
7000
70
70
What is the value of the 2 in 285?A
What is the value of the 6 in 641?S
What is the value of the 1 in 61,238?T
What is the value of the 5 in 95,276?K
What is the value of the 3 in 1,838?I
What is the value of the 8 in 6,891?F
What is the value of the 5 in 352?R
What is the value of the 1 in 713?N
What is the value of the 7 in 379?E
What is the value of the 3 in 63,184?W
What is the value of the 7 in 67,254?L
0/11 letters found
Clue 3
Word problems
The tide patrol solves story problems about missing supplies in the cavern.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Someonescaredthevillainoffwith.
D
19
27
56
6
72
26
D
19
Reef Guard found 12 glowing pearls yesterday and 7 more today. How many glowing pearls in all?D
There were 14 coral prisms. 8 were used up. How many coral prisms are left?S
Reef Guard lined up 7 rows of 8 glowing pearls. How many glowing pearls in all?Y
Reef Guard lined up 9 rows of 3 shell lockets. How many shell lockets in all?R
Reef Guard lined up 8 rows of 9 shell lockets. How many shell lockets in all?A
There were 65 starfish tokens. 39 were used up. How many starfish tokens are left?N
0/6 letters found
Clue 4
Bar model word problems
Guardians sketch bar models of ocean current speeds to narrow down the escape route.
Draw a bar model to solve each word problem. Its answer reveals a letter — write the letters in the boxes to fill in the missing word.
Astrandof hairturnedupatthescene.
S
47
139
103
16
56
103
107
116
R
139
139
N
The red team has 70 glowing pearls and the blue team has 23 glowing pearls. How many more glowing pearls does the red team have?
draw a bar model
Answer:→S
The red team has 113 glowing pearls and the blue team has 10 glowing pearls. How many more glowing pearls does the red team have?
draw a bar model
Answer:→A
The red team has 115 glowing pearls and the blue team has 8 glowing pearls. How many more glowing pearls does the red team have?
draw a bar model
Answer:→M
One group collected 76 coral prisms and another group collected 63 coral prisms. How many coral prisms in all?
draw a bar model
Answer:→E
Reef Guard has 232 coral prisms, packed 2 to a bag. How many bags can be filled?
draw a bar model
Answer:→G
There were 18 starfish tokens in all. 2 starfish tokens were used. How many starfish tokens are left?
draw a bar model
Answer:→F
Reef Guard used 2/4 of the shell lockets on the first day. The other 28 shell lockets were used the next day. How many shell lockets were there in all?
draw a bar model
Answer:→O
0/7 letters found
Clue 5
Division facts (1-12) — the last clue
Dividing the discovered ocean gems evenly among four guard stations uncovers the next 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
60 ÷ 12 = ?
84 ÷ 7 = ?
27 ÷ 3 = ?
4 ÷ 4 = ?
66 ÷ 11 = ?
80 ÷ 10 = ?
99 ÷ 9 = ?
56 ÷ 8 = ?
100 ÷ 10 = ?
4 ÷ 2 = ?
6 ÷ 2 = ?
Step 2 — cross out the sentence with each answer
1.The villain raised a shimmering tide shield, then blew a sharp shell whistle.
2.The villain raised a shimmering tide shield, then cracked a heavy kelp whip.
3.The villain channeled a massive tidal wave, then pointed a gleaming pearl staff.
4.The villain raised a shimmering tide shield, then pointed a gleaming pearl staff.
5.The villain channeled a massive tidal wave, then waved a glowing sea glass wand.
6.The villain sang a bewitching siren song, then cracked a heavy kelp whip.
7.The villain channeled a massive tidal wave, then swung a heavy anchor charm.
8.The villain fired a swift bubble blast, then blew a sharp shell whistle.
9.The villain sang a bewitching siren song, then pointed a gleaming pearl staff.
10.The villain reshaped the sharp reef coral, then cracked a heavy kelp whip.
11.The villain reshaped the sharp reef coral, then swung a heavy anchor charm.
12.The villain raised a shimmering tide shield, then swung a heavy anchor charm.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Coral Cavern Pearl Heist
Culprit: Nixie Reef (Tide Shield · Pearl Staff · Left Fin Striker · Seafoam Green · Dry Sand)
- Clue 1 (Addition): "THE BANDIT DOES NOT USE A KELP WHIP"2130 + 2464 = 4594 (T) · 2472 + 4768 = 7240 (L) · 1964 + 1401 = 3365 (K) · 6353 + 3406 = 9759 (W) · 6154 + 3472 = 9626 (E) · 4596 + 5219 = 9815 (N) · 4062 + 5026 = 9088 (D) · 1198 + 925 = 2123 (U) · 4577 + 4825 = 9402 (P) · 5825 + 3861 = 9686 (A) · 5462 + 4374 = 9836 (S) · 2980 + 6672 = 9652 (O) · 1640 + 1935 = 3575 (H) · 3916 + 1931 = 5847 (B) · 1798 + 1240 = 3038 (I)
- Clue 2 (Place value): "A WITNESS SAW A LEFT FIN STRIKER FLEE"What is the value of the 2 in 285? = 200 (A) · What is the value of the 6 in 641? = 600 (S) · What is the value of the 1 in 61,238? = 1000 (T) · What is the value of the 5 in 95,276? = 5000 (K) · What is the value of the 3 in 1,838? = 30 (I) · What is the value of the 8 in 6,891? = 800 (F) · What is the value of the 5 in 352? = 50 (R) · What is the value of the 1 in 713? = 10 (N) · What is the value of the 7 in 379? = 70 (E) · What is the value of the 3 in 63,184? = 3000 (W) · What is the value of the 7 in 67,254? = 7000 (L)
- Clue 3 (Word problems): "DRY SAND"Reef Guard found 12 glowing pearls yesterday and 7 more today. How many glowing pearls in all? = 19 (D) · There were 14 coral prisms. 8 were used up. How many coral prisms are left? = 6 (S) · Reef Guard lined up 7 rows of 8 glowing pearls. How many glowing pearls in all? = 56 (Y) · Reef Guard lined up 9 rows of 3 shell lockets. How many shell lockets in all? = 27 (R) · Reef Guard lined up 8 rows of 9 shell lockets. How many shell lockets in all? = 72 (A) · There were 65 starfish tokens. 39 were used up. How many starfish tokens are left? = 26 (N)
- Clue 4 (Bar model word problems): "SEAFOAM GREEN"The red team has 70 glowing pearls and the blue team has 23 glowing pearls. How many more glowing pearls does the red team have? = 47 (S) · The red team has 113 glowing pearls and the blue team has 10 glowing pearls. How many more glowing pearls does the red team have? = 103 (A) · The red team has 115 glowing pearls and the blue team has 8 glowing pearls. How many more glowing pearls does the red team have? = 107 (M) · One group collected 76 coral prisms and another group collected 63 coral prisms. How many coral prisms in all? = 139 (E) · Reef Guard has 232 coral prisms, packed 2 to a bag. How many bags can be filled? = 116 (G) · There were 18 starfish tokens in all. 2 starfish tokens were used. How many starfish tokens are left? = 16 (F) · Reef Guard used 2/4 of the shell lockets on the first day. The other 28 shell lockets were used the next day. How many shell lockets were there in all? = 56 (O)
- Clue 5 (Division facts (1-12)): surviving statement (box 4) → Nixie Reef60 ÷ 12 = 5 · 84 ÷ 7 = 12 · 27 ÷ 3 = 9 · 4 ÷ 4 = 1 · 66 ÷ 11 = 6 · 80 ÷ 10 = 8 · 99 ÷ 9 = 11 · 56 ÷ 8 = 7 · 100 ÷ 10 = 10 · 4 ÷ 2 = 2 · 6 ÷ 2 = 3
About this mystery
- Grade level
- Grade 4 math
- Math topics
- Addition, Place value, Word problems, Bar models, Division
- Reading level
- grades 5-6
- Theme
- The Coral Cavern Pearl Heist — set in Coral City Reef
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects