🔎 Murder mysteryGrade 6Reading: grades 1-2PercentagesExponentsOrder of operationsMultiplicationDivision

The Case of the Missing Ruby

The famous Crimson Ruby has vanished from its glass case! The room is locked. Who could have done it? The Mystery Club is on the case to find the master 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	Gear Used	Calling Card	Writing Hand	Hair Color	Weakness
Hudson	laser pointer	silver coin	right handed	gray hair	allergic to cats
Gid	grappling hook	blue ribbon	left handed	dark hair	hates loud noises
Lupin	laser pointer	brass key	left handed	gray hair	hates loud noises
Watson	laser pointer	toy mouse	left handed	red hair	hates loud noises
Clouseau	spy camera	silver coin	left handed	dark hair	hates loud noises
Nancy	smoke bomb	feather pen	right handed	dark hair	hates loud noises
Nora	laser pointer	silver coin	left handed	gray hair	hates loud noises
Hardy	spy camera	toy mouse	left handed	gray hair	hates loud noises
Poirot	grappling hook	blue ribbon	right handed	gray hair	hates loud noises
Nick	laser pointer	brass key	right handed	dark hair	allergic to cats
Columbo	smoke bomb	silver coin	left handed	gray hair	hates loud noises
Velma	grappling hook	feather pen	left handed	red hair	hates loud noises
Marple	grappling hook	feather pen	left handed	gray hair	hates loud noises
Sherlock	smoke bomb	feather pen	left handed	red hair	hates loud noises
Monk	grappling hook	feather pen	left handed	dark hair	afraid of dark
Kojak	smoke bomb	brass key	right handed	red hair	allergic to cats
Holmes	laser pointer	silver coin	left handed	red hair	afraid of dark
Spade	smoke bomb	feather pen	left handed	red hair	allergic to cats
Moriarty	spy camera	feather pen	right handed	red hair	hates loud noises
Adler	grappling hook	silver coin	left handed	gray hair	afraid of dark
Drew	glass cutter	feather pen	left handed	gray hair	allergic to cats

Clue 1

Percentages

The team finds a chart of clues. Some clues are still missing. We must find the percent of clues we have left.

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

20% of 215 =T

10% of 310 =K

25% of 48 =H

50% of 48 =R

10% of 270 =Y

20% of 15 =I

75% of 12 =E

25% of 156 =L

10% of 70 =V

10% of 220 =N

5% of 420 =B

50% of 40 =A

50% of 68 =S

5% of 260 =O

5% of 640 =D

25% of 148 =P

0/16 letters found

Clue 2

Exponents

A secret safe has a digital keypad. The power levels grow very fast. Solve the math box to unlock the door.

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

196

125

243

196

343

100

225

169

100

196

125

169

100

196

169

225

361

196

216

100

128

324

10^2 =T

3^5 =P

3^3 =N

18^2 =D

3^2 =U

7^3 =C

2^5 =W

19^2 =L

6^3 =F

2^7 =A

14^2 =E

4^3 =H

13^2 =I

15^2 =R

5^3 =S

0/15 letters found

Clue 3

Order of operations

To open the heavy wooden desk, you must pull the drawers in a special order. Solve this puzzle to get the steps.

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

8 × 9 - 5 =T

8 × 10 - 15 =F

11 × 9 - 21 =D

12 + 2 × 9 =W

3 + 2 × 4 =E

1 + 2 × 4 =B

8 + 4 × 8 =N

12 × 5 - 6 =A

44 + 4 × 9 =O

6 + 2 × 2 =Y

5 × 8 - 12 =R

1 + 4 × 7 =U

6 + 7 × 2 =M

6 + 2 × 6 =I

51 + 3 × 5 =L

5 × 4 - 5 =H

0/16 letters found

Clue 4

Multiplication facts (1-12)

We count rows of muddy footprints on the rug. Let us multiply the rows to find the total number of prints.

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

108

132

110

132

108

110

132

11 × 6 =W

10 × 11 =H

10 × 2 =V

6 × 9 =L

9 × 9 =G

1 × 7 =U

12 × 8 =T

8 × 3 =O

3 × 5 =I

5 × 5 =S

9 × 12 =N

8 × 2 =Y

12 × 11 =A

4 × 7 =R

2 × 1 =D

8 × 11 =E

10 × 4 =F

0/17 letters found

Clue 5

Division facts (1-12) — the last clue

We must share the magnifying glasses among the junior detectives. Help us split them up evenly to get our last 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

144 ÷ 12 = ?

40 ÷ 5 = ?

81 ÷ 9 = ?

99 ÷ 9 = ?

12 ÷ 6 = ?

32 ÷ 8 = ?

24 ÷ 4 = ?

15 ÷ 5 = ?

90 ÷ 9 = ?

50 ÷ 10 = ?

2 ÷ 2 = ?

Step 2 — cross out the sentence with each answer

1.The villain cut a neat glass circle, then dropped a shiny silver coin.

2.The villain took a secret photo, then left a heavy brass key.

3.The villain threw down a smoke bomb, then placed a small toy mouse.

4.The villain took a secret photo, then dropped a shiny silver coin.

5.The villain swung up the high wall, then tied a bright blue ribbon.

6.The villain shined a red laser, then placed a small toy mouse.

7.The villain took a secret photo, then placed a small toy mouse.

8.The villain shined a red laser, then dropped a shiny silver coin.

9.The villain swung up the high wall, then left a fancy feather pen.

10.The villain cut a neat glass circle, then tied a bright blue ribbon.

11.The villain swung up the high wall, then dropped a shiny silver coin.

12.The villain threw down a smoke bomb, then dropped a shiny silver coin.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Case of the Missing Ruby

Culprit: Hardy (spy camera · toy mouse · left handed · gray hair · hates loud noises)

Clue 1 (Percentages): "THE VILLAIN DOES NOT DROP A BRASS KEY"
20% of 215 = 43 (T) · 10% of 310 = 31 (K) · 25% of 48 = 12 (H) · 50% of 48 = 24 (R) · 10% of 270 = 27 (Y) · 20% of 15 = 3 (I) · 75% of 12 = 9 (E) · 25% of 156 = 39 (L) · 10% of 70 = 7 (V) · 10% of 220 = 22 (N) · 5% of 420 = 21 (B) · 50% of 40 = 20 (A) · 50% of 68 = 34 (S) · 5% of 260 = 13 (O) · 5% of 640 = 32 (D) · 25% of 148 = 37 (P)
Clue 2 (Exponents): "THE SUSPECT WRITES WITH THEIR LEFT HAND"
10^2 = 100 (T) · 3^5 = 243 (P) · 3^3 = 27 (N) · 18^2 = 324 (D) · 3^2 = 9 (U) · 7^3 = 343 (C) · 2^5 = 32 (W) · 19^2 = 361 (L) · 6^3 = 216 (F) · 2^7 = 128 (A) · 14^2 = 196 (E) · 4^3 = 64 (H) · 13^2 = 169 (I) · 15^2 = 225 (R) · 5^3 = 125 (S)
Clue 3 (Order of operations): "THE THIEF RAN AWAY FROM THE LOUD BELL"
8 × 9 - 5 = 67 (T) · 8 × 10 - 15 = 65 (F) · 11 × 9 - 21 = 78 (D) · 12 + 2 × 9 = 30 (W) · 3 + 2 × 4 = 11 (E) · 1 + 2 × 4 = 9 (B) · 8 + 4 × 8 = 40 (N) · 12 × 5 - 6 = 54 (A) · 44 + 4 × 9 = 80 (O) · 6 + 2 × 2 = 10 (Y) · 5 × 8 - 12 = 28 (R) · 1 + 4 × 7 = 29 (U) · 6 + 7 × 2 = 20 (M) · 6 + 2 × 6 = 18 (I) · 51 + 3 × 5 = 66 (L) · 5 × 4 - 5 = 15 (H)
Clue 4 (Multiplication facts (1-12)): "WE FOUND A SILVERY GRAY HAIR ON THE WALL"
11 × 6 = 66 (W) · 10 × 11 = 110 (H) · 10 × 2 = 20 (V) · 6 × 9 = 54 (L) · 9 × 9 = 81 (G) · 1 × 7 = 7 (U) · 12 × 8 = 96 (T) · 8 × 3 = 24 (O) · 3 × 5 = 15 (I) · 5 × 5 = 25 (S) · 9 × 12 = 108 (N) · 8 × 2 = 16 (Y) · 12 × 11 = 132 (A) · 4 × 7 = 28 (R) · 2 × 1 = 2 (D) · 8 × 11 = 88 (E) · 10 × 4 = 40 (F)
Clue 5 (Division facts (1-12)): surviving statement (box 7) → Hardy
144 ÷ 12 = 12 · 40 ÷ 5 = 8 · 81 ÷ 9 = 9 · 99 ÷ 9 = 11 · 12 ÷ 6 = 2 · 32 ÷ 8 = 4 · 24 ÷ 4 = 6 · 15 ÷ 5 = 3 · 90 ÷ 9 = 10 · 50 ÷ 10 = 5 · 2 ÷ 2 = 1

About this mystery

Grade level: Grade 6 math
Math topics: Percentages, Exponents, Order of operations, Multiplication, Division
Reading level: grades 1-2
Theme: The Case of the Missing Ruby — set in The spooky library inside Whisper Manor
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

More free printable math mysteries

6th grade worksheets Multiplication worksheets Division worksheets Percentages worksheets Exponents worksheets Order of operations worksheets All worksheets →

The Great Bone Mystery

Grade 6

The Great Homework Folder Mix-Up

Grade 6

The Great Block Griefer

Grade 6

The Case of the Golden Fish

Grade 6