Grade 7Reading: grades 7-9IntegersPercentagesOrder of operationsExponentsTwo-step equations

The Abyss Vault Heist

A high-tech energy core was stolen from the ocean floor laboratory. Track the clue logs to find out which suspect pulled off the dive!

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	Submarine Gear	Specialist Skill	Watch Wrist	Wetsuit Hood	Glove Type
Diver Owen	Thermal Shield	Deep Diving	Left Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Specialist Zoe	Plasma Torch	Code Breaking	Right Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Specialist Chloe	Grapple Arm	Deep Diving	Right Wrist Watch	Bright Yellow Hood	Rubber Grip Gloves
Specialist Sam	Grapple Arm	Code Breaking	Left Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Diver Liam	Stealth Propulsion	Code Breaking	Left Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Pilot Ethan	Thermal Shield	Deep Diving	Left Wrist Watch	Bright Yellow Hood	Thermal Padded Gloves
Engineer Frank	Stealth Propulsion	Laser Cutting	Left Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Capt Aronnax	Sonar Array	Laser Cutting	Right Wrist Watch	Dark Black Hood	Rubber Grip Gloves
Engineer Kai	Sonar Array	Pressure Tuning	Left Wrist Watch	Neon Blue Hood	Rubber Grip Gloves
Commander Jacques	Plasma Torch	Laser Cutting	Left Wrist Watch	Bright Yellow Hood	Kevlar Mesh Gloves
Tech Mateo	Grapple Arm	Code Breaking	Right Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Tech Caleb	Thermal Shield	Pressure Tuning	Right Wrist Watch	Neon Blue Hood	Rubber Grip Gloves
Tech Maya Lin	Grapple Arm	Deep Diving	Left Wrist Watch	Bright Yellow Hood	Rubber Grip Gloves
Dr James Reed	Plasma Torch	Pressure Tuning	Right Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Pilot Tara	Stealth Propulsion	Laser Cutting	Left Wrist Watch	Neon Blue Hood	Rubber Grip Gloves
Dr Victor Vance	Plasma Torch	Hydro Navigation	Left Wrist Watch	Neon Blue Hood	Thermal Padded Gloves
Diver Leo	Thermal Shield	Hydro Navigation	Right Wrist Watch	Neon Blue Hood	Rubber Grip Gloves
Dr Sylvia Earle	Grapple Arm	Laser Cutting	Right Wrist Watch	Dark Black Hood	Kevlar Mesh Gloves
Pilot Jax	Stealth Propulsion	Pressure Tuning	Left Wrist Watch	Bright Yellow Hood	Thermal Padded Gloves
Pilot Nora	Thermal Shield	Pressure Tuning	Left Wrist Watch	Neon Blue Hood	Kevlar Mesh Gloves
Officer Ben	Thermal Shield	Hydro Navigation	Right Wrist Watch	Neon Blue Hood	Thermal Padded Gloves

Clue 1

Integers

The submarine temperature logs recorded extreme elevation changes above and below sea level to reveal the first evidence.

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

(-9) + 17 =T

(-6) + 34 =P

19 - (-11) =D

(-4) + 29 =H

(-7) + 31 =V

1 - (-2) =E

(-1) + 27 =I

(-3) + 17 =K

(-13) + 42 =O

(-2) + 23 =A

(-6) + 21 =G

(-12) + 19 =S

6 - (-5) =N

(-8) + 28 =L

(-5) + 9 =U

0/15 letters found

Clue 2

Percentages

Security sensors calculated the percentage of battery depletion across each underwater sector during the breach.

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

25% of 76 =T

10% of 220 =H

50% of 64 =O

10% of 230 =L

5% of 880 =F

50% of 34 =W

25% of 212 =S

5% of 480 =C

25% of 28 =N

10% of 330 =R

5% of 260 =A

40% of 50 =I

20% of 80 =E

0/13 letters found

Clue 3

Order of operations

Decoding the station security sequence required evaluating multi-step energy equations in order.

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

100

11 + 5 × 3 =T

5 × 11 - 18 =I

11 × 11 - 30 =V

10 × 2 - 6 =H

12 × 3 - 8 =S

11 × 9 - 30 =G

12 × 7 - 7 =O

28 + 3 × 4 =L

14 + 9 × 5 =A

10 × 11 - 17 =F

5 × 8 - 27 =M

11 × 8 - 2 =D

17 + 4 × 7 =P

96 + 2 × 2 =R

4 × 9 - 12 =E

0/15 letters found

Clue 4

Exponents

Pressure growth calculations followed exponential curves as the rogue sub descended into the trench.

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

361

256

361

289

243

256

169

289

100

324

169

128

100

169

125

256

361

169

125

100

19^2 =N

2^5 =E

3^3 =F

9^2 =H

2^7 =S

10^2 =C

6^2 =R

4^2 =G

5^3 =T

13^2 =A

16^2 =O

3^5 =L

17^2 =B

8^2 =I

2^3 =D

7^2 =U

18^2 =W

0/17 letters found

Clue 5

Two-step equations — the last clue

Solving the station automated ballast gate codes required solving two-step balance equations.

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 + 12 = 39, x = ?

6x + 10 = 58, x = ?

4x + 8 = 20, x = ?

3x + 9 = 42, x = ?

2x + 12 = 20, x = ?

2x + 2 = 22, x = ?

3x + 5 = 20, x = ?

5x + 9 = 44, x = ?

6x + 4 = 76, x = ?

5x + 1 = 31, x = ?

2x + 4 = 6, x = ?

Step 2 — cross out the sentence with each answer

1.The villain engaged stealth propulsion, then managed pressure tuning.

2.The villain fired the plasma torch, then handled hydro navigation.

3.The villain engaged stealth propulsion, then performed laser cutting.

4.The villain activated the sonar array, then completed code breaking.

5.The villain charged the thermal shield, then handled hydro navigation.

6.The villain activated the sonar array, then handled hydro navigation.

7.The villain deployed the grapple arm, then handled hydro navigation.

8.The villain deployed the grapple arm, then completed code breaking.

9.The villain engaged stealth propulsion, then completed code breaking.

10.The villain fired the plasma torch, then completed code breaking.

11.The villain fired the plasma torch, then managed pressure tuning.

12.The villain charged the thermal shield, then performed laser cutting.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Abyss Vault Heist

Culprit: Dr Victor Vance (Plasma Torch · Hydro Navigation · Left Wrist Watch · Neon Blue Hood · Thermal Padded Gloves)

Clue 1 (Integers): "THE VILLAIN DOES NOT USE DEEP DIVING SKILLS"
(-9) + 17 = 8 (T) · (-6) + 34 = 28 (P) · 19 - (-11) = 30 (D) · (-4) + 29 = 25 (H) · (-7) + 31 = 24 (V) · 1 - (-2) = 3 (E) · (-1) + 27 = 26 (I) · (-3) + 17 = 14 (K) · (-13) + 42 = 29 (O) · (-2) + 23 = 21 (A) · (-6) + 21 = 15 (G) · (-12) + 19 = 7 (S) · 6 - (-5) = 11 (N) · (-8) + 28 = 20 (L) · (-5) + 9 = 4 (U)
Clue 2 (Percentages): "THE WITNESS SAW A WATCH ON THE LEFT WRIST"
25% of 76 = 19 (T) · 10% of 220 = 22 (H) · 50% of 64 = 32 (O) · 10% of 230 = 23 (L) · 5% of 880 = 44 (F) · 50% of 34 = 17 (W) · 25% of 212 = 53 (S) · 5% of 480 = 24 (C) · 25% of 28 = 7 (N) · 10% of 330 = 33 (R) · 5% of 260 = 13 (A) · 40% of 50 = 20 (I) · 20% of 80 = 16 (E)
Clue 3 (Order of operations): "THERMAL PADDED GLOVES RESISTED THE FROST TRAP"
11 + 5 × 3 = 26 (T) · 5 × 11 - 18 = 37 (I) · 11 × 11 - 30 = 91 (V) · 10 × 2 - 6 = 14 (H) · 12 × 3 - 8 = 28 (S) · 11 × 9 - 30 = 69 (G) · 12 × 7 - 7 = 77 (O) · 28 + 3 × 4 = 40 (L) · 14 + 9 × 5 = 59 (A) · 10 × 11 - 17 = 93 (F) · 5 × 8 - 27 = 13 (M) · 11 × 8 - 2 = 86 (D) · 17 + 4 × 7 = 45 (P) · 96 + 2 × 2 = 100 (R) · 4 × 9 - 12 = 24 (E)
Clue 4 (Exponents): "NEON BLUE HOOD FABRIC WAS CAUGHT ON HATCH"
19^2 = 361 (N) · 2^5 = 32 (E) · 3^3 = 27 (F) · 9^2 = 81 (H) · 2^7 = 128 (S) · 10^2 = 100 (C) · 6^2 = 36 (R) · 4^2 = 16 (G) · 5^3 = 125 (T) · 13^2 = 169 (A) · 16^2 = 256 (O) · 3^5 = 243 (L) · 17^2 = 289 (B) · 8^2 = 64 (I) · 2^3 = 8 (D) · 7^2 = 49 (U) · 18^2 = 324 (W)
Clue 5 (Two-step equations): surviving statement (box 2) → Dr Victor Vance
3x + 12 = 39, x = 9 · 6x + 10 = 58, x = 8 · 4x + 8 = 20, x = 3 · 3x + 9 = 42, x = 11 · 2x + 12 = 20, x = 4 · 2x + 2 = 22, x = 10 · 3x + 5 = 20, x = 5 · 5x + 9 = 44, x = 7 · 6x + 4 = 76, x = 12 · 5x + 1 = 31, x = 6 · 2x + 4 = 6, x = 1

About this mystery

Grade level: Grade 7 math
Math topics: Integers, Percentages, Order of operations, Exponents, Two-step equations
Reading level: grades 7-9
Theme: The Abyss Vault Heist — set in Nautilus Deep Sea Trench Station
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

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