🔎 The trenchesGrade 5Reading: grades 5-6AdditionSubtractionMultiplicationFractions of a number
The Trench Mystery
A vital brass signal whistle has vanished from the Sector Nine command dugout. A sneaky spy, known as the Phantom Courier, swiped it right under the watch of our scouts. It is up to you to wade through the mud, crack the clues, and find the culprit before night falls.
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 | Signal Duty | Special Tool | Mud Splatter | Helmet Style | Favorite Ration |
|---|---|---|---|---|---|
| Edward | Runner Patrol | Rubber Mud Boots | Splattered on Right Side | Woolen Watch Cap | Canned Peaches |
| Charles | Pigeon Carrier | Pocket Watch | Splattered on Left Side | Woolen Watch Cap | Canned Peaches |
| Percy | Pigeon Carrier | Pocket Watch | Splattered on Right Side | Officer Peak Cap | Peppermint Drops |
| Albert | Morse Code | Steel Trench Shovel | Splattered on Left Side | Flat Steel Helmet | Canned Peaches |
| Douglas | Pigeon Carrier | Brass Compass | Splattered on Right Side | Officer Peak Cap | Peppermint Drops |
| Sidney | Wire Repair | Brass Compass | Splattered on Left Side | Woolen Watch Cap | Peppermint Drops |
| George | Pigeon Carrier | Steel Trench Shovel | Splattered on Left Side | Flat Steel Helmet | Canned Peaches |
| Leonard | Periscope Watch | Steel Trench Shovel | Splattered on Left Side | Woolen Watch Cap | Canned Peaches |
| Herbert | Runner Patrol | Brass Compass | Splattered on Left Side | Woolen Watch Cap | Canned Peaches |
| Reginald | Periscope Watch | Steel Trench Shovel | Splattered on Left Side | Flat Steel Helmet | Hardtack Biscuits |
| Victor | Morse Code | Pocket Watch | Splattered on Right Side | Officer Peak Cap | Canned Peaches |
| Frederick | Runner Patrol | Rubber Mud Boots | Splattered on Left Side | Woolen Watch Cap | Canned Peaches |
| Stanley | Periscope Watch | Rubber Mud Boots | Splattered on Right Side | Woolen Watch Cap | Canned Peaches |
| William | Pigeon Carrier | Leather Satchel | Splattered on Right Side | Flat Steel Helmet | Hardtack Biscuits |
| Ernest | Pigeon Carrier | Rubber Mud Boots | Splattered on Left Side | Woolen Watch Cap | Canned Peaches |
| Arthur | Runner Patrol | Steel Trench Shovel | Splattered on Right Side | Flat Steel Helmet | Hardtack Biscuits |
| Thomas | Periscope Watch | Brass Compass | Splattered on Right Side | Officer Peak Cap | Hardtack Biscuits |
| Bernard | Morse Code | Brass Compass | Splattered on Left Side | Flat Steel Helmet | Canned Peaches |
| Gordon | Pigeon Carrier | Rubber Mud Boots | Splattered on Left Side | Flat Steel Helmet | Canned Peaches |
| Alfred | Runner Patrol | Steel Trench Shovel | Splattered on Left Side | Woolen Watch Cap | Hardtack Biscuits |
| Walter | Periscope Watch | Brass Compass | Splattered on Left Side | Officer Peak Cap | Peppermint Drops |
Clue 1
Addition
We count the total wooden planks recovered from the mud to rebuild our pathway and find a dropped note.
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
8672
7589
8202
3793
3040
8424
4848
2300
8202
4848
3057
3040
8202
4103
9152
3040
T
8672
3793
8451
4848
4848
7449
8451
6386
3040
3793
4881
8202
T
8672
6047
8451
T
8672
3793
7589
3451 + 5221 =T
2969 + 5455 =U
2442 + 3605 =W
5312 + 2890 =E
1137 + 1163 =I
4259 + 2127 =P
2004 + 1036 =O
4326 + 4826 =N
3330 + 1551 =K
1947 + 1110 =D
3299 + 1549 =R
2094 + 1699 =C
2366 + 5083 =Y
3174 + 4415 =H
2836 + 1267 =S
4874 + 3577 =A
0/16 letters found
Clue 2
Subtraction
By measuring the drop in rainwater levels inside the main trench, we calculate how much mud has been cleared.
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
4451
4067
8251
6010
7230
8079
6338
T
4451
6010
8337
4376
2120
6338
2838
8079
4754
T
4451
4067
8251
2511
8251
7967
T
4451
6010
2908
2838
8251
6205 - 1754 =T
7146 - 3079 =H
12856 - 4777 =O
8801 - 464 =A
8592 - 625 =F
10536 - 2285 =E
8355 - 3979 =W
2931 - 811 =M
8733 - 2395 =U
6362 - 352 =S
6687 - 4176 =L
5801 - 1047 =N
11260 - 4030 =C
5916 - 3008 =I
6870 - 4032 =D
0/15 letters found
Clue 3
Multiplication facts (1-12)
We count the stacks of dry wool socks, arranged in perfect rows, to see what the thief brushed past.
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
132
15
48
49
54
6
2
6
27
15
10
88
54
48
A
132
44
1
48
32
144
A
132
32
96
27
32
44
10
11
48
72
48
96
12 × 11 =A
8 × 4 =S
2 × 3 =T
6 × 9 =P
12 × 12 =W
1 × 11 =V
3 × 5 =N
8 × 9 =R
2 × 1 =Y
12 × 4 =E
11 × 4 =C
7 × 7 =M
12 × 8 =D
11 × 8 =F
9 × 3 =I
5 × 2 =O
1 × 1 =H
0/17 letters found
Clue 4
Fractions of a number
Only a fraction of the carrier pigeons returned safely with messages about the thief's escape route.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
R
28
36
24
26
35
35
23
39
40
6
36
R
28
7
26
36
R
28
36
7
4
38
12
12
36
24
35
4
26
40
R
28
36
7/10 of 40 =R
2/4 of 14 =S
2/8 of 144 =E
1/5 of 200 =I
1/3 of 12 =N
3/4 of 32 =D
5/10 of 46 =L
2/6 of 114 =A
1/5 of 175 =O
2/8 of 48 =G
2/4 of 78 =F
3/10 of 20 =B
2/5 of 65 =W
0/13 letters found
Clue 5
Fractions of a number — the last clue
Our scouts examined a fraction of the boots left in the supply tent to track down the size of the suspect.
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
1/3 of 6 = ?
9/10 of 10 = ?
2/10 of 55 = ?
5/10 of 12 = ?
2/10 of 50 = ?
3/6 of 10 = ?
2/8 of 32 = ?
3/10 of 40 = ?
3/6 of 14 = ?
3/6 of 2 = ?
5/10 of 8 = ?
Step 2 — cross out the sentence with each answer
1.The villain climbed the wooden ladder, then headed toward the camp.
2.The villain crept through the dugout, then slipped away in the rain.
3.The villain sneaked past the sentry, then slipped away in the rain.
4.The villain climbed the wooden ladder, then slipped away in the rain.
5.The villain crept through the dugout, then escaped into the mist.
6.The villain slipped through the wire, then vanished near the outpost.
7.The villain splashed down the trench, then scrambled into the fog.
8.The villain splashed down the trench, then headed toward the camp.
9.The villain climbed the wooden ladder, then vanished near the outpost.
10.The villain sneaked past the sentry, then scrambled into the fog.
11.The villain crept through the dugout, then scrambled into the fog.
12.The villain sneaked past the sentry, then headed toward the camp.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Trench Mystery
Culprit: Ernest (Pigeon Carrier · Rubber Mud Boots · Splattered on Left Side · Woolen Watch Cap · Canned Peaches)
- Clue 1 (Addition): "THE COURIER DOES NOT CARRY A POCKET WATCH"3451 + 5221 = 8672 (T) · 2969 + 5455 = 8424 (U) · 2442 + 3605 = 6047 (W) · 5312 + 2890 = 8202 (E) · 1137 + 1163 = 2300 (I) · 4259 + 2127 = 6386 (P) · 2004 + 1036 = 3040 (O) · 4326 + 4826 = 9152 (N) · 3330 + 1551 = 4881 (K) · 1947 + 1110 = 3057 (D) · 3299 + 1549 = 4848 (R) · 2094 + 1699 = 3793 (C) · 2366 + 5083 = 7449 (Y) · 3174 + 4415 = 7589 (H) · 2836 + 1267 = 4103 (S) · 4874 + 3577 = 8451 (A)
- Clue 2 (Subtraction): "THE SCOUT SAW MUD ON THE LEFT SIDE"6205 - 1754 = 4451 (T) · 7146 - 3079 = 4067 (H) · 12856 - 4777 = 8079 (O) · 8801 - 464 = 8337 (A) · 8592 - 625 = 7967 (F) · 10536 - 2285 = 8251 (E) · 8355 - 3979 = 4376 (W) · 2931 - 811 = 2120 (M) · 8733 - 2395 = 6338 (U) · 6362 - 352 = 6010 (S) · 6687 - 4176 = 2511 (L) · 5801 - 1047 = 4754 (N) · 11260 - 4030 = 7230 (C) · 5916 - 3008 = 2908 (I) · 6870 - 4032 = 2838 (D)
- Clue 3 (Multiplication facts (1-12)): "AN EMPTY TIN OF PEACHES WAS DISCOVERED"12 × 11 = 132 (A) · 8 × 4 = 32 (S) · 2 × 3 = 6 (T) · 6 × 9 = 54 (P) · 12 × 12 = 144 (W) · 1 × 11 = 11 (V) · 3 × 5 = 15 (N) · 8 × 9 = 72 (R) · 2 × 1 = 2 (Y) · 12 × 4 = 48 (E) · 11 × 4 = 44 (C) · 7 × 7 = 49 (M) · 12 × 8 = 96 (D) · 11 × 8 = 88 (F) · 9 × 3 = 27 (I) · 5 × 2 = 10 (O) · 1 × 1 = 1 (H)
- Clue 4 (Fractions of a number): "RED WOOL FIBERS WERE SNAGGED ON WIRE"7/10 of 40 = 28 (R) · 2/4 of 14 = 7 (S) · 2/8 of 144 = 36 (E) · 1/5 of 200 = 40 (I) · 1/3 of 12 = 4 (N) · 3/4 of 32 = 24 (D) · 5/10 of 46 = 23 (L) · 2/6 of 114 = 38 (A) · 1/5 of 175 = 35 (O) · 2/8 of 48 = 12 (G) · 2/4 of 78 = 39 (F) · 3/10 of 20 = 6 (B) · 2/5 of 65 = 26 (W)
- Clue 5 (Fractions of a number): surviving statement (box 3) → Ernest1/3 of 6 = 2 · 9/10 of 10 = 9 · 2/10 of 55 = 11 · 5/10 of 12 = 6 · 2/10 of 50 = 10 · 3/6 of 10 = 5 · 2/8 of 32 = 8 · 3/10 of 40 = 12 · 3/6 of 14 = 7 · 3/6 of 2 = 1 · 5/10 of 8 = 4
About this mystery
- Grade level
- Grade 5 math
- Math topics
- Addition, Subtraction, Multiplication, Fractions of a number
- Reading level
- grades 5-6
- Theme
- The Trench Mystery — set in the foggy and muddy trenches of Sector Nine
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects