Grade 1Reading: grades 1-2AdditionSubtractionMultiplicationPlace valueDivision
The Great Treehouse Mystery
Someone hid the official camp trophy inside Whispering Pines! The Head Ranger needs your help to follow clues, solve math puzzles, and spot the trickster.
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 | Camp Skill | Trail Trick | Bandana Color | Hair Style | Weakness |
|---|---|---|---|---|---|
| Sam | Flashlight Signaling | Mud Sliding | Wears Yellow Bandana | Braided Hair | Bug Spray |
| Nora | Flashlight Signaling | Marshmallow Toasting | Wears Yellow Bandana | Braided Hair | Bug Spray |
| Ivy | Compass Navigation | Bubble Trapping | Wears Red Bandana | Spiky Hair | Bug Spray |
| Nina | Rope Climbing | Mud Sliding | Wears Red Bandana | Curly Hair | Loud Whistle |
| Eli | Compass Navigation | Bubble Trapping | Wears Yellow Bandana | Braided Hair | Bug Spray |
| Ella | Zip Line Gliding | Marshmallow Toasting | Wears Red Bandana | Braided Hair | Flashlight Beam |
| Owen | Map Reading | Bubble Trapping | Wears Yellow Bandana | Curly Hair | Loud Whistle |
| Finn | Flashlight Signaling | Bubble Trapping | Wears Yellow Bandana | Braided Hair | Bug Spray |
| Ava | Rope Climbing | Bubble Trapping | Wears Yellow Bandana | Spiky Hair | Flashlight Beam |
| Kai | Flashlight Signaling | Marshmallow Toasting | Wears Yellow Bandana | Braided Hair | Flashlight Beam |
| Liam | Flashlight Signaling | Berry Throwing | Wears Red Bandana | Curly Hair | Flashlight Beam |
| Luke | Zip Line Gliding | Bubble Trapping | Wears Yellow Bandana | Spiky Hair | Bug Spray |
| Maya | Rope Climbing | Tree Scrambling | Wears Red Bandana | Braided Hair | Bug Spray |
| Mia | Zip Line Gliding | Marshmallow Toasting | Wears Yellow Bandana | Braided Hair | Bug Spray |
| Chloe | Rope Climbing | Bubble Trapping | Wears Red Bandana | Curly Hair | Loud Whistle |
| Ruby | Compass Navigation | Bubble Trapping | Wears Yellow Bandana | Spiky Hair | Loud Whistle |
| Sofia | Map Reading | Mud Sliding | Wears Yellow Bandana | Curly Hair | Bug Spray |
| Ben | Zip Line Gliding | Tree Scrambling | Wears Yellow Bandana | Spiky Hair | Flashlight Beam |
| Toby | Map Reading | Marshmallow Toasting | Wears Yellow Bandana | Braided Hair | Bug Spray |
| Jack | Rope Climbing | Tree Scrambling | Wears Yellow Bandana | Braided Hair | Flashlight Beam |
| Leo | Rope Climbing | Mud Sliding | Wears Yellow Bandana | Braided Hair | Flashlight Beam |
Clue 1
Addition
We counted all the shiny badges found on the camp trail to solve the first mystery.
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
10
12
13
11
7
6
6
15
7
18
20
17
13
2
18
17
T
10
8
2
13
5
8
5
5
6
13
T
10
16
15
3
2
3 + 7 =T
4 + 4 =U
5 + 8 =E
6 + 14 =D
3 + 4 =I
1 + 1 =S
8 + 8 =R
5 + 1 =L
4 + 7 =V
4 + 8 =H
12 + 6 =N
10 + 7 =O
3 + 2 =B
9 + 6 =A
1 + 2 =P
0/15 letters found
Clue 2
Subtraction
We took away the broken compasses from the gear box to check what was 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.
W
11
5
6
18
16
13
13
13
2
W
11
2
9
8
5
12
15
6
17
16
10
10
1
W
11
9
2
18
7
2
18
2
13 - 2 =W
20 - 2 =N
4 - 3 =O
15 - 8 =D
18 - 5 =S
19 - 4 =H
17 - 1 =E
15 - 5 =L
17 - 9 =R
13 - 1 =G
3 - 1 =A
6 - 1 =I
10 - 4 =T
19 - 2 =Y
15 - 6 =B
0/15 letters found
Clue 3
Multiplication facts (1-12)
We checked four rows of tent pegs to find a hidden message.
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
11
7
56
33
27
121
15
18
33
108
15
121
63
99
21
100
63
33
6
63
15
9
18
42
80
144
144
15
80
6
1 × 11 =B
12 × 9 =C
7 × 3 =T
11 × 11 =R
10 × 8 =I
7 × 9 =E
6 × 7 =V
5 × 3 =A
7 × 1 =U
3 × 6 =Y
10 × 10 =H
8 × 7 =G
3 × 9 =P
3 × 3 =K
9 × 11 =D
3 × 11 =S
12 × 12 =L
3 × 2 =N
0/18 letters found
Clue 4
Place value
The digital lock on the supply cabin showed a two digit code.
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
38
20
30
88
39
92
39
44
30
88
20
64
30
96
24
63
81
79
39
79
92
30
20
43
44
92
93
63
28
What number has 3 tens and 8 ones?B
What number has 4 tens and 3 ones?T
What number has 4 tens and 4 ones?H
What number has 2 tens and 0 ones?R
What number has 2 tens and 4 ones?F
What number has 6 tens and 4 ones?W
What number has 9 tens and 6 ones?S
What number has 7 tens and 9 ones?N
What number has 8 tens and 8 ones?I
What number has 3 tens and 9 ones?D
What number has 2 tens and 8 ones?G
What number has 6 tens and 3 ones?O
What number has 8 tens and 1 one?U
What number has 3 tens and 0 ones?A
What number has 9 tens and 3 ones?L
What number has 9 tens and 2 ones?E
0/16 letters found
Clue 5
Division facts (1-12) — the last clue
We shared the trail snack bags equally among the team to unlock the final hint.
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
40 ÷ 10 = ?
54 ÷ 9 = ?
10 ÷ 10 = ?
14 ÷ 2 = ?
108 ÷ 9 = ?
11 ÷ 1 = ?
30 ÷ 3 = ?
64 ÷ 8 = ?
4 ÷ 2 = ?
21 ÷ 7 = ?
27 ÷ 3 = ?
Step 2 — cross out the sentence with each answer
1.The villain flashed the coded signal, then slid through the deep mud.
2.The villain guided the trail group, then toasted giant marshmallows.
3.The villain scaled the tall rope net, then slid through the deep mud.
4.The villain traced the secret map, then toasted giant marshmallows.
5.The villain flashed the coded signal, then toasted giant marshmallows.
6.The villain zoomed down the zip line, then toasted giant marshmallows.
7.The villain traced the secret map, then launched sticky bubbles.
8.The villain flashed the coded signal, then launched sticky bubbles.
9.The villain scaled the tall rope net, then toasted giant marshmallows.
10.The villain scaled the tall rope net, then launched sticky bubbles.
11.The villain guided the trail group, then slid through the deep mud.
12.The villain traced the secret map, then scrambled up the tree bark.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Great Treehouse Mystery
Culprit: Nora (Flashlight Signaling · Marshmallow Toasting · Wears Yellow Bandana · Braided Hair · Bug Spray)
- Clue 1 (Addition): "THE VILLAIN DOES NOT USE BUBBLE TRAPS"3 + 7 = 10 (T) · 4 + 4 = 8 (U) · 5 + 8 = 13 (E) · 6 + 14 = 20 (D) · 3 + 4 = 7 (I) · 1 + 1 = 2 (S) · 8 + 8 = 16 (R) · 5 + 1 = 6 (L) · 4 + 7 = 11 (V) · 4 + 8 = 12 (H) · 12 + 6 = 18 (N) · 10 + 7 = 17 (O) · 3 + 2 = 5 (B) · 9 + 6 = 15 (A) · 1 + 2 = 3 (P)
- Clue 2 (Subtraction): "WITNESS SAW A BRIGHT YELLOW BANDANA"13 - 2 = 11 (W) · 20 - 2 = 18 (N) · 4 - 3 = 1 (O) · 15 - 8 = 7 (D) · 18 - 5 = 13 (S) · 19 - 4 = 15 (H) · 17 - 1 = 16 (E) · 15 - 5 = 10 (L) · 17 - 9 = 8 (R) · 13 - 1 = 12 (G) · 3 - 1 = 2 (A) · 6 - 1 = 5 (I) · 10 - 4 = 6 (T) · 19 - 2 = 17 (Y) · 15 - 6 = 9 (B)
- Clue 3 (Multiplication facts (1-12)): "BUG SPRAY SCARED THE SNEAKY VILLAIN"1 × 11 = 11 (B) · 12 × 9 = 108 (C) · 7 × 3 = 21 (T) · 11 × 11 = 121 (R) · 10 × 8 = 80 (I) · 7 × 9 = 63 (E) · 6 × 7 = 42 (V) · 5 × 3 = 15 (A) · 7 × 1 = 7 (U) · 3 × 6 = 18 (Y) · 10 × 10 = 100 (H) · 8 × 7 = 56 (G) · 3 × 9 = 27 (P) · 3 × 3 = 9 (K) · 9 × 11 = 99 (D) · 3 × 11 = 33 (S) · 12 × 12 = 144 (L) · 3 × 2 = 6 (N)
- Clue 4 (Place value): "BRAIDED HAIR WAS FOUND NEAR THE LOG"What number has 3 tens and 8 ones? = 38 (B) · What number has 4 tens and 3 ones? = 43 (T) · What number has 4 tens and 4 ones? = 44 (H) · What number has 2 tens and 0 ones? = 20 (R) · What number has 2 tens and 4 ones? = 24 (F) · What number has 6 tens and 4 ones? = 64 (W) · What number has 9 tens and 6 ones? = 96 (S) · What number has 7 tens and 9 ones? = 79 (N) · What number has 8 tens and 8 ones? = 88 (I) · What number has 3 tens and 9 ones? = 39 (D) · What number has 2 tens and 8 ones? = 28 (G) · What number has 6 tens and 3 ones? = 63 (O) · What number has 8 tens and 1 one? = 81 (U) · What number has 3 tens and 0 ones? = 30 (A) · What number has 9 tens and 3 ones? = 93 (L) · What number has 9 tens and 2 ones? = 92 (E)
- Clue 5 (Division facts (1-12)): surviving statement (box 5) → Nora40 ÷ 10 = 4 · 54 ÷ 9 = 6 · 10 ÷ 10 = 1 · 14 ÷ 2 = 7 · 108 ÷ 9 = 12 · 11 ÷ 1 = 11 · 30 ÷ 3 = 10 · 64 ÷ 8 = 8 · 4 ÷ 2 = 2 · 21 ÷ 7 = 3 · 27 ÷ 3 = 9
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Addition, Subtraction, Multiplication, Place value, Division
- Reading level
- grades 1-2
- Theme
- The Great Treehouse Mystery — set in Whispering Pines Adventure Camp
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects