🔎 Mudre mysteryGrade 5Reading: grades 7-9Fractions of a numberOrder of operationsMultiplicationRoundingDivision
The Mystery of Blackwood Manor
Lord Blackwood's rare diamond has been stolen from the study during a sudden power outage. Only twenty-four distinguished guests were present. As the lead detective, you must examine the evidence, question the suspects, and crack the case before the morning train departs.
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 | Disguise Style | Calling Card | Dominant Hand | Wig Color | Scent Profile |
|---|---|---|---|---|---|
| Harriet Vane | Beaded Vintage Gown | Ornate Brass Key | Right-handed Writer | Auburn Red Hair | Smell of Lavender Tea |
| Joe Hardy | Velvet Opera Cloak | Poison-tipped Quill | Left-handed Writer | Auburn Red Hair | Smell of Peppermint Oil |
| Cordelia Gray | Silk Tuxedo Jacket | Monogrammed Handkerchief | Left-handed Writer | Silver Gray Hair | Smell of Lavender Tea |
| Frank Hardy | Feathered Venetian Mask | Monogrammed Handkerchief | Right-handed Writer | Auburn Red Hair | Smell of Lavender Tea |
| Phryne Fisher | Silk Tuxedo Jacket | Poison-tipped Quill | Left-handed Writer | Auburn Red Hair | Smell of Lavender Tea |
| Sam Spade | Velvet Opera Cloak | Ornate Brass Key | Right-handed Writer | Silver Gray Hair | Smell of Lavender Tea |
| Lord Peter Wimsey | Tweed Detective Trench | Monogrammed Handkerchief | Left-handed Writer | Auburn Red Hair | Smell of Lavender Tea |
| Sherlock Holmes | Feathered Venetian Mask | Ornate Brass Key | Left-handed Writer | Auburn Red Hair | Smell of Lavender Tea |
| Mycroft Holmes | Feathered Venetian Mask | Poison-tipped Quill | Right-handed Writer | Silver Gray Hair | Smell of Pipe Tobacco |
| Perry Mason | Tweed Detective Trench | Wax-sealed Envelope | Left-handed Writer | Auburn Red Hair | Smell of Lavender Tea |
| Arsene Lupin | Beaded Vintage Gown | Silver Pocketwatch | Left-handed Writer | Silver Gray Hair | Smell of Lavender Tea |
| Arthur Hastings | Silk Tuxedo Jacket | Ornate Brass Key | Right-handed Writer | Jet Black Hair | Smell of Pipe Tobacco |
| Reginald Jeeves | Tweed Detective Trench | Monogrammed Handkerchief | Left-handed Writer | Auburn Red Hair | Smell of Peppermint Oil |
| John Watson | Feathered Venetian Mask | Wax-sealed Envelope | Right-handed Writer | Jet Black Hair | Smell of Peppermint Oil |
| Hercule Poirot | Silk Tuxedo Jacket | Wax-sealed Envelope | Right-handed Writer | Silver Gray Hair | Smell of Peppermint Oil |
| Agatha Christie | Velvet Opera Cloak | Silver Pocketwatch | Right-handed Writer | Silver Gray Hair | Smell of Pipe Tobacco |
| Nancy Drew | Beaded Vintage Gown | Monogrammed Handkerchief | Right-handed Writer | Jet Black Hair | Smell of Lavender Tea |
| Nero Wolfe | Feathered Venetian Mask | Poison-tipped Quill | Left-handed Writer | Jet Black Hair | Smell of Peppermint Oil |
| Roderick Glossop | Tweed Detective Trench | Silver Pocketwatch | Right-handed Writer | Auburn Red Hair | Smell of Pipe Tobacco |
| C Auguste Dupin | Tweed Detective Trench | Ornate Brass Key | Left-handed Writer | Silver Gray Hair | Smell of Peppermint Oil |
| Irene Adler | Feathered Venetian Mask | Silver Pocketwatch | Left-handed Writer | Auburn Red Hair | Smell of Lavender Tea |
Clue 1
Fractions of a number
We found a partially burned list of dinner guests in the fireplace, but only a fraction of the name cards survived the flames.
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
4
7
9
T
4
7
6
9
14
15
6
15
23
16
T
4
33
9
21
19
9
21
24
6
33
19
9
31
37
16
10
30
9
T
4
11
21
T
4
10
7
1/2 of 8 =T
5/6 of 36 =K
5/10 of 46 =N
2/6 of 45 =D
4/8 of 38 =V
3/6 of 74 =P
2/10 of 35 =H
6/10 of 35 =A
2/6 of 93 =R
4/8 of 32 =O
1/8 of 112 =F
1/3 of 27 =E
1/3 of 18 =I
1/5 of 165 =L
2/10 of 55 =W
2/5 of 25 =C
5/10 of 48 =S
0/17 letters found
Clue 2
Order of operations
The heavy iron lockbox on the desk requires us to twist the dials in a strict order of mathematical operations to reveal its secrets.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
S
43
7
19
76
35
19
15
59
22
31
S
43
76
17
S
43
78
58
19
78
58
59
19
42
59
S
43
60
19
42
78
58
76
22
15
19
15
33 + 5 × 2 =S
34 + 4 × 6 =H
8 + 3 × 9 =R
25 + 3 × 2 =K
8 × 6 - 26 =N
5 + 3 × 4 =Y
6 + 9 × 4 =F
52 + 4 × 2 =L
7 + 6 × 2 =E
7 × 6 - 27 =D
6 × 11 - 7 =I
2 × 10 - 13 =M
8 × 11 - 10 =T
22 + 6 × 9 =A
0/14 letters found
Clue 3
Multiplication facts (1-12)
To estimate the value of the missing silver, we counted the rows of empty velvet slots in the display case.
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
81
25
84
50
36
36
T
81
50
54
84
35
35
50
50
T
81
32
36
22
77
35
10
36
90
35
11
108
84
22
96
84
32
T
81
84
11
9 × 9 =T
2 × 11 =N
11 × 1 =A
9 × 4 =O
4 × 8 =R
7 × 5 =L
9 × 6 =M
8 × 12 =D
5 × 5 =H
11 × 7 =G
7 × 12 =E
1 × 10 =Y
9 × 10 =F
5 × 10 =S
9 × 12 =V
0/15 letters found
Clue 4
Rounding
The grandfather clock was damaged during the escape, so its broken gear only chimed the nearest hour.
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
3000
7000
290
1100
2300
300
30
5000
170
3700
300
90
370
7000
5000
2300
110
2300
20
300
20
7000
30
1700
5000
3700
20
170
700
20
5000
300
30
Round 3,389 to the nearest thousandW
Round 89 to the nearest tenG
Round 1,703 to the nearest hundredH
Round 2,278 to the nearest hundredU
Round 6,633 to the nearest thousandE
Round 107 to the nearest tenB
Round 30 to the nearest tenD
Round 3,731 to the nearest hundredI
Round 327 to the nearest hundredN
Round 366 to the nearest tenL
Round 743 to the nearest hundredT
Round 292 to the nearest tenF
Round 167 to the nearest tenS
Round 19 to the nearest tenR
Round 1,110 to the nearest hundredO
Round 5,073 to the nearest thousandA
0/16 letters found
Clue 5
Division facts (1-12) — the last clue
To search the sprawling estate systematically, we divided our team of investigators evenly across the different floors.
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
66 ÷ 6 = ?
63 ÷ 7 = ?
8 ÷ 4 = ?
3 ÷ 3 = ?
40 ÷ 5 = ?
72 ÷ 12 = ?
5 ÷ 1 = ?
24 ÷ 8 = ?
72 ÷ 6 = ?
56 ÷ 8 = ?
20 ÷ 2 = ?
Step 2 — cross out the sentence with each answer
1.The villain swished their velvet opera cloak, then dropped an ornate brass key.
2.The villain fastened their tweed detective trench, then dropped a wax-sealed envelope.
3.The villain adjusted their beaded vintage gown, then dropped a silver pocketwatch.
4.The villain buttoned their silk tuxedo jacket, then dropped a poison-tipped quill.
5.The villain swished their velvet opera cloak, then dropped a poison-tipped quill.
6.The villain buttoned their silk tuxedo jacket, then dropped a wax-sealed envelope.
7.The villain secured their feathered venetian mask, then dropped a monogrammed handkerchief.
8.The villain adjusted their beaded vintage gown, then dropped an ornate brass key.
9.The villain fastened their tweed detective trench, then dropped a monogrammed handkerchief.
10.The villain fastened their tweed detective trench, then dropped a poison-tipped quill.
11.The villain secured their feathered venetian mask, then dropped an ornate brass key.
12.The villain fastened their tweed detective trench, then dropped an ornate brass key.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of Blackwood Manor
Culprit: Phryne Fisher (Silk Tuxedo Jacket · Poison-tipped Quill · Left-handed Writer · Auburn Red Hair · Smell of Lavender Tea)
- Clue 1 (Fractions of a number): "THE THIEF DID NOT LEAVE A SILVER POCKETWATCH"1/2 of 8 = 4 (T) · 5/6 of 36 = 30 (K) · 5/10 of 46 = 23 (N) · 2/6 of 45 = 15 (D) · 4/8 of 38 = 19 (V) · 3/6 of 74 = 37 (P) · 2/10 of 35 = 7 (H) · 6/10 of 35 = 21 (A) · 2/6 of 93 = 31 (R) · 4/8 of 32 = 16 (O) · 1/8 of 112 = 14 (F) · 1/3 of 27 = 9 (E) · 1/3 of 18 = 6 (I) · 1/5 of 165 = 33 (L) · 2/10 of 55 = 11 (W) · 2/5 of 25 = 10 (C) · 5/10 of 48 = 24 (S)
- Clue 2 (Order of operations): "SMEARED INK SAYS THE THIEF IS LEFT HANDED"33 + 5 × 2 = 43 (S) · 34 + 4 × 6 = 58 (H) · 8 + 3 × 9 = 35 (R) · 25 + 3 × 2 = 31 (K) · 8 × 6 - 26 = 22 (N) · 5 + 3 × 4 = 17 (Y) · 6 + 9 × 4 = 42 (F) · 52 + 4 × 2 = 60 (L) · 7 + 6 × 2 = 19 (E) · 7 × 6 - 27 = 15 (D) · 6 × 11 - 7 = 59 (I) · 2 × 10 - 13 = 7 (M) · 8 × 11 - 10 = 78 (T) · 22 + 6 × 9 = 76 (A)
- Clue 3 (Multiplication facts (1-12)): "THE SOOT SMELLS STRONGLY OF LAVENDER TEA"9 × 9 = 81 (T) · 2 × 11 = 22 (N) · 11 × 1 = 11 (A) · 9 × 4 = 36 (O) · 4 × 8 = 32 (R) · 7 × 5 = 35 (L) · 9 × 6 = 54 (M) · 8 × 12 = 96 (D) · 5 × 5 = 25 (H) · 11 × 7 = 77 (G) · 7 × 12 = 84 (E) · 1 × 10 = 10 (Y) · 9 × 10 = 90 (F) · 5 × 10 = 50 (S) · 9 × 12 = 108 (V)
- Clue 4 (Rounding): "WE FOUND A SINGLE AUBURN RED HAIR STRAND"Round 3,389 to the nearest thousand = 3000 (W) · Round 89 to the nearest ten = 90 (G) · Round 1,703 to the nearest hundred = 1700 (H) · Round 2,278 to the nearest hundred = 2300 (U) · Round 6,633 to the nearest thousand = 7000 (E) · Round 107 to the nearest ten = 110 (B) · Round 30 to the nearest ten = 30 (D) · Round 3,731 to the nearest hundred = 3700 (I) · Round 327 to the nearest hundred = 300 (N) · Round 366 to the nearest ten = 370 (L) · Round 743 to the nearest hundred = 700 (T) · Round 292 to the nearest ten = 290 (F) · Round 167 to the nearest ten = 170 (S) · Round 19 to the nearest ten = 20 (R) · Round 1,110 to the nearest hundred = 1100 (O) · Round 5,073 to the nearest thousand = 5000 (A)
- Clue 5 (Division facts (1-12)): surviving statement (box 4) → Phryne Fisher66 ÷ 6 = 11 · 63 ÷ 7 = 9 · 8 ÷ 4 = 2 · 3 ÷ 3 = 1 · 40 ÷ 5 = 8 · 72 ÷ 12 = 6 · 5 ÷ 1 = 5 · 24 ÷ 8 = 3 · 72 ÷ 6 = 12 · 56 ÷ 8 = 7 · 20 ÷ 2 = 10
About this mystery
- Grade level
- Grade 5 math
- Math topics
- Fractions of a number, Order of operations, Multiplication, Rounding, Division
- Reading level
- grades 7-9
- Theme
- The Mystery of Blackwood Manor — set in A grand Victorian estate during a rainy-day masquerade
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects