🏴☠️ PiratesGrade 9Reading: grades 5-6Two-step equationsExponentsSquare rootsIntegers
The Mystery of Black Cove
Someone snuck onto the flagship at midnight and stole the Golden Quadrant! The Harbor Master called upon all deckhands to solve the clues, track down the rogue pirate, and restore order to Black Cove.
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 | Combat Move | Escape Gear | Dominant Hand | Beard or Hair | Secret Vulnerability |
|---|---|---|---|---|---|
| William Kidd | Anchor Drop | Flare Signal | Right Handed | Red Braids | Compass Magnet |
| Francois lOlonnais | Hook Swipe | Smoke Bomb | Right Handed | Black Beard | Seagull Whistle |
| Thomas Tew | Pistol Shot | Grappling Hook | Right Handed | Black Beard | Seagull Whistle |
| Stede Bonnet | Cannon Blast | Net Trap | Left Handed | Black Beard | Seagull Whistle |
| Christopher Condent | Pistol Shot | Flare Signal | Right Handed | Red Braids | Seagull Whistle |
| Grace OMalley | Pistol Shot | Smoke Bomb | Right Handed | Red Braids | Seagull Whistle |
| Ching Shih | Cannon Blast | Smoke Bomb | Left Handed | Black Beard | Seagull Whistle |
| Samuel Bellamy | Hook Swipe | Net Trap | Right Handed | Black Beard | Seagull Whistle |
| Woodes Rogers | Cannon Blast | Grappling Hook | Right Handed | Red Braids | Citrus Juice |
| Edward Low | Cannon Blast | Flare Signal | Right Handed | Black Beard | Seagull Whistle |
| Charles Vane | Cutlass Slash | Smoke Bomb | Right Handed | Red Braids | Compass Magnet |
| Howell Davis | Cannon Blast | Net Trap | Right Handed | Black Beard | Compass Magnet |
| Cheung Po Tsai | Cutlass Slash | Smoke Bomb | Right Handed | Silver Locks | Citrus Juice |
| Bartholomew Roberts | Cutlass Slash | Grappling Hook | Right Handed | Red Braids | Compass Magnet |
| Calico Jack | Pistol Shot | Powder Keg | Left Handed | Silver Locks | Seagull Whistle |
| Blackbeard | Cutlass Slash | Net Trap | Left Handed | Black Beard | Citrus Juice |
| Anne Bonny | Pistol Shot | Flare Signal | Right Handed | Black Beard | Compass Magnet |
| John Evans | Hook Swipe | Smoke Bomb | Right Handed | Red Braids | Seagull Whistle |
| Mary Read | Hook Swipe | Grappling Hook | Right Handed | Red Braids | Seagull Whistle |
| John Rackham | Hook Swipe | Grappling Hook | Left Handed | Red Braids | Compass Magnet |
| Benjamin Hornigold | Cannon Blast | Smoke Bomb | Right Handed | Black Beard | Seagull Whistle |
Clue 1
Two-step equations
To unlock the quartermaster's chest, solve this two-step equation balance.
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
22
12
21
5
4
16
16
19
4
7
13
4
13
7
8
T
22
11
17
21
19
6
20
19
10
10
16
4
7
6
12
8
8
15
6x + 2 = 134, x =T
5x + 3 = 53, x =P
6x + 9 = 105, x =L
7x + 7 = 126, x =S
8x + 5 = 45, x =V
5x + 9 = 44, x =N
9x + 5 = 122, x =D
2x + 7 = 29, x =U
3x + 9 = 69, x =R
6x + 9 = 81, x =H
9x + 7 = 196, x =E
8x + 2 = 50, x =G
7x + 4 = 109, x =K
2x + 12 = 50, x =A
3x + 11 = 23, x =I
4x + 12 = 44, x =O
0/16 letters found
Clue 2
Exponents
The supply crates double each hour. Evaluate this exponent to check the total.
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
36
9
196
100
216
121
121
121
125
W
36
125
400
9
289
144
196
144
125
100
128
216
128
484
64
196
361
125
121
121
121
196
400
9
256
216
6^2 =W
6^3 =E
14^2 =T
11^2 =S
19^2 =L
5^3 =A
22^2 =C
3^2 =I
16^2 =K
20^2 =R
12^2 =H
17^2 =G
10^2 =N
8^2 =U
2^7 =D
0/15 letters found
Clue 3
Square roots
The square treasure grid hides a code. Find the square root to reveal it.
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
9
22
3
A
9
13
4
2
2
6
20
8
22
5
2
3
18
A
9
16
3
5
20
3
10
8
2
2
A
9
8
17
25
3
5
25
3
A
9
5
sqrt(81) =A
sqrt(400) =H
sqrt(100) =V
sqrt(324) =M
sqrt(484) =S
sqrt(9) =E
sqrt(64) =I
sqrt(289) =N
sqrt(16) =U
sqrt(169) =G
sqrt(625) =R
sqrt(25) =T
sqrt(36) =W
sqrt(4) =L
sqrt(256) =D
0/15 letters found
Clue 4
Integers
The tide mark drops and rises. Use integers to calculate the final depth.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
B
21
24
6
7
37
B
21
1
6
4
19
18
6
12
4
39
6
22
3
9
26
15
19
9
15
36
18
1
19
1
7
37
8 - (-13) =B
(-12) + 21 =O
(-7) + 33 =U
(-8) + 32 =L
(-2) + 21 =D
(-8) + 15 =C
38 - (-1) =W
(-8) + 14 =A
(-3) + 15 =I
(-10) + 13 =F
(-7) + 11 =R
28 - (-8) =T
(-11) + 33 =S
(-9) + 46 =K
(-11) + 26 =N
(-14) + 32 =H
(-10) + 11 =E
0/17 letters found
Clue 5
Two-step equations — the last clue
Decipher this two-step equation from the ship's ledger to locate the final 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
3x + 9 = 30, x = ?
2x + 6 = 24, x = ?
4x + 9 = 21, x = ?
2x + 9 = 21, x = ?
8x + 2 = 10, x = ?
9x + 11 = 119, x = ?
8x + 3 = 83, x = ?
4x + 10 = 26, x = ?
2x + 4 = 26, x = ?
7x + 1 = 15, x = ?
3x + 8 = 23, x = ?
Step 2 — cross out the sentence with each answer
1.The villain fired a cannon blast, then cast a heavy net trap.
2.The villain swung a sharp cutlass, then tossed a steel grappling hook.
3.The villain swiped an iron hook, then threw a dense smoke bomb.
4.The villain swiped an iron hook, then lit an explosive powder keg.
5.The villain shot a flintlock pistol, then threw a dense smoke bomb.
6.The villain fired a cannon blast, then tossed a steel grappling hook.
7.The villain fired a cannon blast, then threw a dense smoke bomb.
8.The villain swiped an iron hook, then cast a heavy net trap.
9.The villain fired a cannon blast, then launched a bright flare signal.
10.The villain swung a sharp cutlass, then launched a bright flare signal.
11.The villain dropped a heavy anchor, then launched a bright flare signal.
12.The villain dropped a heavy anchor, then tossed a steel grappling hook.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of Black Cove
Culprit: Samuel Bellamy (Hook Swipe · Net Trap · Right Handed · Black Beard · Seagull Whistle)
- Clue 1 (Two-step equations): "THE VILLAIN DID NOT USE A GRAPPLING HOOK"6x + 2 = 134, x = 22 (T) · 5x + 3 = 53, x = 10 (P) · 6x + 9 = 105, x = 16 (L) · 7x + 7 = 126, x = 17 (S) · 8x + 5 = 45, x = 5 (V) · 5x + 9 = 44, x = 7 (N) · 9x + 5 = 122, x = 13 (D) · 2x + 7 = 29, x = 11 (U) · 3x + 9 = 69, x = 20 (R) · 6x + 9 = 81, x = 12 (H) · 9x + 7 = 196, x = 21 (E) · 8x + 2 = 50, x = 6 (G) · 7x + 4 = 109, x = 15 (K) · 2x + 12 = 50, x = 19 (A) · 3x + 11 = 23, x = 4 (I) · 4x + 12 = 44, x = 8 (O)
- Clue 2 (Exponents): "WITNESS SAW A RIGHT HANDED CUTLASS STRIKE"6^2 = 36 (W) · 6^3 = 216 (E) · 14^2 = 196 (T) · 11^2 = 121 (S) · 19^2 = 361 (L) · 5^3 = 125 (A) · 22^2 = 484 (C) · 3^2 = 9 (I) · 16^2 = 256 (K) · 20^2 = 400 (R) · 12^2 = 144 (H) · 17^2 = 289 (G) · 10^2 = 100 (N) · 8^2 = 64 (U) · 2^7 = 128 (D)
- Clue 3 (Square roots): "A SEAGULL WHISTLE MADE THE VILLAIN RETREAT"sqrt(81) = 9 (A) · sqrt(400) = 20 (H) · sqrt(100) = 10 (V) · sqrt(324) = 18 (M) · sqrt(484) = 22 (S) · sqrt(9) = 3 (E) · sqrt(64) = 8 (I) · sqrt(289) = 17 (N) · sqrt(16) = 4 (U) · sqrt(169) = 13 (G) · sqrt(625) = 25 (R) · sqrt(25) = 5 (T) · sqrt(36) = 6 (W) · sqrt(4) = 2 (L) · sqrt(256) = 16 (D)
- Clue 4 (Integers): "BLACK BEARD HAIR WAS FOUND ON THE DECK"8 - (-13) = 21 (B) · (-12) + 21 = 9 (O) · (-7) + 33 = 26 (U) · (-8) + 32 = 24 (L) · (-2) + 21 = 19 (D) · (-8) + 15 = 7 (C) · 38 - (-1) = 39 (W) · (-8) + 14 = 6 (A) · (-3) + 15 = 12 (I) · (-10) + 13 = 3 (F) · (-7) + 11 = 4 (R) · 28 - (-8) = 36 (T) · (-11) + 33 = 22 (S) · (-9) + 46 = 37 (K) · (-11) + 26 = 15 (N) · (-14) + 32 = 18 (H) · (-10) + 11 = 1 (E)
- Clue 5 (Two-step equations): surviving statement (box 8) → Samuel Bellamy3x + 9 = 30, x = 7 · 2x + 6 = 24, x = 9 · 4x + 9 = 21, x = 3 · 2x + 9 = 21, x = 6 · 8x + 2 = 10, x = 1 · 9x + 11 = 119, x = 12 · 8x + 3 = 83, x = 10 · 4x + 10 = 26, x = 4 · 2x + 4 = 26, x = 11 · 7x + 1 = 15, x = 2 · 3x + 8 = 23, x = 5
About this mystery
- Grade level
- Grade 9 math
- Math topics
- Two-step equations, Exponents, Square roots, Integers
- Reading level
- grades 5-6
- Theme
- The Mystery of Black Cove — set in Black Cove Harbor
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects