🌊 MermaidsGrade 10Reading: grades 7-9Pythagorean theoremSquare rootsExponentsOrder of operations

The Theft of the Heart Pearl

The shimmering Coral Vault has been looted, and the precious Great Heart Pearl is gone. A rogue mer-scout was seen escaping into the deep kelp forest, leaving behind traces of unique ocean magic and distinct physical clues. We must track them down before they cross the open ocean.

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 magic	specialized gear	swimming style	tail fin color	magic allergy
Ariel	whale-whispering	conch horn	right-finned stroke	crimson coral	silver-kelp
Thalassa	bioluminescence	sea-glass dagger	right-finned stroke	seafoam green	silver-kelp
Rikki	bioluminescence	prism shell	left-finned stroke	crimson coral	silver-kelp
Madison	coral-shaping	conch horn	right-finned stroke	shimmering violet	sunlight-magic
Lyla	coral-shaping	sea-glass dagger	right-finned stroke	seafoam green	silver-kelp
Syrena	tide-calling	kelp lasso	left-finned stroke	crimson coral	sunlight-magic
Undine	tide-calling	kelp lasso	right-finned stroke	crimson coral	sunlight-magic
Cleo	current-weaving	prism shell	left-finned stroke	crimson coral	deep-salt
Melusine	whale-whispering	conch horn	right-finned stroke	shimmering violet	sunlight-magic
Coralia	bioluminescence	kelp lasso	left-finned stroke	shimmering violet	silver-kelp
Muriel	current-weaving	sea-glass dagger	left-finned stroke	crimson coral	silver-kelp
Emma	current-weaving	sea-glass dagger	left-finned stroke	crimson coral	sunlight-magic
Delphine	coral-shaping	pearl compass	left-finned stroke	shimmering violet	sunlight-magic
Marina	current-weaving	sea-glass dagger	left-finned stroke	seafoam green	sunlight-magic
Mako	bioluminescence	conch horn	left-finned stroke	seafoam green	sunlight-magic
Oceanus	bioluminescence	pearl compass	right-finned stroke	crimson coral	sunlight-magic
Nerida	coral-shaping	prism shell	right-finned stroke	crimson coral	deep-salt
Nereus	tide-calling	prism shell	right-finned stroke	crimson coral	sunlight-magic
Caspian	coral-shaping	conch horn	right-finned stroke	crimson coral	sunlight-magic
Kai	current-weaving	sea-glass dagger	right-finned stroke	seafoam green	sunlight-magic
Triton	tide-calling	pearl compass	right-finned stroke	crimson coral	sunlight-magic

Clue 1

Pythagorean theorem

To map the suspect's escape route across the reef, we must calculate the diagonal distance between the ancient shipwreck and the blue hole using our coordinate trackers.

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

123

116

legs 14 and 48, hypotenuse =T

legs 8 and 15, hypotenuse =H

legs 9 and 12, hypotenuse =D

legs 5 and 12, hypotenuse =A

legs 25 and 60, hypotenuse =E

legs 12 and 35, hypotenuse =V

legs 10 and 24, hypotenuse =S

legs 32 and 60, hypotenuse =M

legs 27 and 120, hypotenuse =F

legs 80 and 84, hypotenuse =R

legs 20 and 48, hypotenuse =I

legs 24 and 32, hypotenuse =P

legs 20 and 21, hypotenuse =L

legs 24 and 70, hypotenuse =O

legs 18 and 24, hypotenuse =N

0/15 letters found

Clue 2

Square roots

The guards found a square formation of glowing jellyfish blocking the eastern trench. Finding the side length of this square array reveals the thief's 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.

sqrt(484) =T

sqrt(16) =H

sqrt(100) =N

sqrt(36) =S

sqrt(49) =D

sqrt(289) =F

sqrt(361) =M

sqrt(169) =W

sqrt(196) =G

sqrt(9) =K

sqrt(400) =R

sqrt(324) =I

sqrt(576) =C

sqrt(81) =O

sqrt(256) =P

sqrt(25) =A

sqrt(121) =U

sqrt(225) =E

0/18 letters found

Clue 3

Exponents

The magical energy ripples outward, doubling in power with every league it travels. Calculating the exponential growth of these waves helps us pinpoint the source.

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

256

125

243

169

125

361

243

144

361

625

484

216

625

125

512

289

343

243

125

512

289

216

169

512

125

441

16^2 =V

5^3 =I

2^3 =N

13^2 =A

19^2 =F

3^5 =L

21^2 =C

2^9 =G

7^3 =U

3^3 =B

6^3 =M

4^2 =S

17^2 =H

5^4 =R

22^2 =O

2^5 =T

12^2 =E

0/17 letters found

Clue 4

Order of operations

We discovered a locked sea-chest belonging to the suspect. The key combination requires us to solve the tidal equations in the exact, ancient order of the seas.

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

115

101

4 × 9 - 17 =C

86 + 3 × 5 =H

9 × 10 - 13 =R

9 × 10 - 6 =D

10 × 9 - 18 =F

3 × 12 - 5 =M

19 + 6 × 8 =E

53 + 5 × 6 =S

42 + 3 × 5 =W

21 + 2 × 6 =L

9 × 7 - 13 =I

59 + 7 × 5 =N

12 × 11 - 17 =O

36 + 8 × 4 =A

29 + 4 × 2 =T

0/15 letters found

Clue 5

Square roots — the last clue

A square patch of ocean floor has been swept clean of sand. Determining the root dimensions of this cleared zone gives us the final coordinate of the suspect's 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

sqrt(4) = ?

sqrt(81) = ?

sqrt(100) = ?

sqrt(25) = ?

sqrt(121) = ?

sqrt(64) = ?

sqrt(144) = ?

sqrt(16) = ?

sqrt(49) = ?

sqrt(9) = ?

sqrt(1) = ?

Step 2 — cross out the sentence with each answer

1.The villain summons a massive undercurrent, then cuts through nets with a sea-glass dagger.

2.The villain shapes a barrier of sharp coral, then signals allies with a conch horn.

3.The villain whispers to a pod of blue whales, then cuts through nets with a sea-glass dagger.

4.The villain shapes a barrier of sharp coral, then cuts through nets with a sea-glass dagger.

5.The villain summons a massive undercurrent, then blinds pursuers with a prism shell.

6.The villain calls down a rushing high tide, then navigates home using a pearl compass.

7.The villain calls down a rushing high tide, then signals allies with a conch horn.

8.The villain summons a massive undercurrent, then escapes using a kelp lasso.

9.The villain lights up the dark water with bioluminescence, then navigates home using a pearl compass.

10.The villain calls down a rushing high tide, then escapes using a kelp lasso.

11.The villain shapes a barrier of sharp coral, then blinds pursuers with a prism shell.

12.The villain shapes a barrier of sharp coral, then escapes using a kelp lasso.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Theft of the Heart Pearl

Culprit: Triton (tide-calling · pearl compass · right-finned stroke · crimson coral · sunlight-magic)

Clue 1 (Pythagorean theorem): "THE THIEF DOES NOT HAVE A PRISM SHELL"
legs 14 and 48, hypotenuse = 50 (T) · legs 8 and 15, hypotenuse = 17 (H) · legs 9 and 12, hypotenuse = 15 (D) · legs 5 and 12, hypotenuse = 13 (A) · legs 25 and 60, hypotenuse = 65 (E) · legs 12 and 35, hypotenuse = 37 (V) · legs 10 and 24, hypotenuse = 26 (S) · legs 32 and 60, hypotenuse = 68 (M) · legs 27 and 120, hypotenuse = 123 (F) · legs 80 and 84, hypotenuse = 116 (R) · legs 20 and 48, hypotenuse = 52 (I) · legs 24 and 32, hypotenuse = 40 (P) · legs 20 and 21, hypotenuse = 29 (L) · legs 24 and 70, hypotenuse = 74 (O) · legs 18 and 24, hypotenuse = 30 (N)
Clue 2 (Square roots): "THE SUSPECT SWIMS WITH A RIGHT FINNED STROKE"
sqrt(484) = 22 (T) · sqrt(16) = 4 (H) · sqrt(100) = 10 (N) · sqrt(36) = 6 (S) · sqrt(49) = 7 (D) · sqrt(289) = 17 (F) · sqrt(361) = 19 (M) · sqrt(169) = 13 (W) · sqrt(196) = 14 (G) · sqrt(9) = 3 (K) · sqrt(400) = 20 (R) · sqrt(324) = 18 (I) · sqrt(576) = 24 (C) · sqrt(81) = 9 (O) · sqrt(256) = 16 (P) · sqrt(25) = 5 (A) · sqrt(121) = 11 (U) · sqrt(225) = 15 (E)
Clue 3 (Exponents): "VILLAIN FLEES FROM BRIGHT SUNLIGHT MAGIC"
16^2 = 256 (V) · 5^3 = 125 (I) · 2^3 = 8 (N) · 13^2 = 169 (A) · 19^2 = 361 (F) · 3^5 = 243 (L) · 21^2 = 441 (C) · 2^9 = 512 (G) · 7^3 = 343 (U) · 3^3 = 27 (B) · 6^3 = 216 (M) · 4^2 = 16 (S) · 17^2 = 289 (H) · 5^4 = 625 (R) · 22^2 = 484 (O) · 2^5 = 32 (T) · 12^2 = 144 (E)
Clue 4 (Order of operations): "CRIMSON CORAL FLARES WERE LEFT IN THE SAND"
4 × 9 - 17 = 19 (C) · 86 + 3 × 5 = 101 (H) · 9 × 10 - 13 = 77 (R) · 9 × 10 - 6 = 84 (D) · 10 × 9 - 18 = 72 (F) · 3 × 12 - 5 = 31 (M) · 19 + 6 × 8 = 67 (E) · 53 + 5 × 6 = 83 (S) · 42 + 3 × 5 = 57 (W) · 21 + 2 × 6 = 33 (L) · 9 × 7 - 13 = 50 (I) · 59 + 7 × 5 = 94 (N) · 12 × 11 - 17 = 115 (O) · 36 + 8 × 4 = 68 (A) · 29 + 4 × 2 = 37 (T)
Clue 5 (Square roots): surviving statement (box 6) → Triton
sqrt(4) = 2 · sqrt(81) = 9 · sqrt(100) = 10 · sqrt(25) = 5 · sqrt(121) = 11 · sqrt(64) = 8 · sqrt(144) = 12 · sqrt(16) = 4 · sqrt(49) = 7 · sqrt(9) = 3 · sqrt(1) = 1

About this mystery

Grade level: Grade 10 math
Math topics: Pythagorean theorem, Square roots, Exponents, Order of operations
Reading level: grades 7-9
Theme: The Theft of the Heart Pearl — set in Sirena Trench
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

More free printable math mysteries

10th grade worksheets Exponents worksheets Order of operations worksheets Square roots worksheets Pythagorean theorem worksheets All worksheets →

The Case of the Golden Catnip Mouse

Grade 10

The Echo Canyon Astrolabe Heist

Grade 10

The Championship Trophy Caper

Grade 10

Sky-Pirates of the Stratosphere

Grade 10