Grade 1Reading: grades 1-2AdditionSubtractionSkip countingPlace valueMissing addends
The Treehouse Club Caper
Oh no! Someone took the Golden Megaphone from the Fort Captain! The Treehouse Club must find out who did it so we can start our camp adventure. Let us search for clues together!
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 | Club Skill | Special Gear | Scout Badge | Hair Style | Silly Weakness |
|---|---|---|---|---|---|
| Abby | tree sliding | walkie talkie | wears a green badge | braided hair | scared of frogs |
| Toby | secret decoding | spy glass | wears a blue badge | spiky hair | tickled by feathers |
| Luke | secret decoding | spy glass | wears a blue badge | wavy hair | dislikes itchy grass |
| Jake | tree sliding | walkie talkie | wears a blue badge | braided hair | dislikes itchy grass |
| Leo | bridge building | walkie talkie | wears a blue badge | spiky hair | dislikes itchy grass |
| Ben | bridge building | spy glass | wears a green badge | braided hair | scared of frogs |
| Finn | secret decoding | glow stick | wears a blue badge | braided hair | scared of frogs |
| Emma | bridge building | spy glass | wears a green badge | wavy hair | tickled by feathers |
| Nora | map reading | walkie talkie | wears a blue badge | wavy hair | scared of frogs |
| Kira | map reading | walkie talkie | wears a blue badge | wavy hair | tickled by feathers |
| Sam | secret decoding | laser pointer | wears a green badge | wavy hair | dislikes itchy grass |
| Noah | tree sliding | laser pointer | wears a blue badge | spiky hair | scared of frogs |
| Owen | tree sliding | water balloon | wears a blue badge | wavy hair | scared of frogs |
| Mia | bridge building | glow stick | wears a green badge | wavy hair | tickled by feathers |
| Ryan | secret decoding | glow stick | wears a blue badge | wavy hair | dislikes itchy grass |
| Zoey | map reading | walkie talkie | wears a blue badge | wavy hair | dislikes itchy grass |
| Lily | rope climbing | spy glass | wears a green badge | wavy hair | scared of frogs |
| Ella | bridge building | walkie talkie | wears a green badge | wavy hair | dislikes itchy grass |
| Ruby | rope climbing | walkie talkie | wears a green badge | wavy hair | dislikes itchy grass |
| Eli | tree sliding | water balloon | wears a blue badge | wavy hair | dislikes itchy grass |
| Jack | secret decoding | laser pointer | wears a blue badge | wavy hair | dislikes itchy grass |
Clue 1
Addition
We need to add up the footprints on the path. Count the old boots and the new sneakers to find the total.
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
5
6
12
16
2
12
20
11
15
10
20
2
14
9
T
5
14
4
12
16
2
4
T
5
18
16
12
20
16
8
15
13
17
20
16
16
3 + 2 =T
10 + 7 =L
5 + 8 =G
4 + 10 =D
8 + 8 =S
9 + 6 =Y
5 + 1 =H
9 + 11 =A
6 + 4 =B
6 + 2 =P
11 + 7 =U
7 + 5 =E
8 + 3 =K
3 + 1 =O
4 + 5 =I
1 + 1 =N
0/16 letters found
Clue 2
Subtraction
Some shiny gold coins fell out of our pocket. We had ten but now we have less. Subtract to see what is missing.
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
6
5
17
1
18
2
2
8
18
19
15
17
8
12
16
8
14
2
4
17
14
8
11
10
17
11 - 5 =T
20 - 2 =I
13 - 2 =D
12 - 7 =H
18 - 1 =E
18 - 3 =W
12 - 8 =U
19 - 3 =S
10 - 2 =A
4 - 2 =L
14 - 4 =G
20 - 1 =N
15 - 1 =B
17 - 5 =R
8 - 7 =V
0/15 letters found
Clue 3
Skip counting
The treehouse club counts secret maps by twos. Let us skip count to get the total number of maps.
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
100
35
36
55
80
10
10
26
80
8
14
80
12
10
80
6
36
12
80
T
100
21
35
27
70
28
36
36
8
70
28
26
12
12
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120T
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, ___, 80, 90G
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, ___, 30, 32R
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, ___, 30, 33Y
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42E
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30A
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, ___, 60, 65V
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100I
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27C
Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12N
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18D
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14L
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, ___, 14, 16S
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45H
Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10K
0/15 letters found
Clue 4
Place value
Our wooden blocks are in neat stacks of ten. Count the tens and the single blocks left over to read the map.
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
90
66
19
91
41
48
83
W
90
28
60
39
86
28
80
51
48
66
28
51
50
86
66
50
51
66
66
86
91
41
58
66
What number has 9 tens and 0 ones?W
What number has 6 tens and 6 ones?E
What number has 6 tens and 0 ones?V
What number has 2 tens and 8 ones?A
What number has 5 tens and 0 ones?T
What number has 4 tens and 1 one?U
What number has 3 tens and 9 ones?Y
What number has 5 tens and 8 ones?S
What number has 4 tens and 8 ones?N
What number has 9 tens and 1 one?O
What number has 8 tens and 3 ones?D
What number has 8 tens and 0 ones?I
What number has 1 ten and 9 ones?F
What number has 5 tens and 1 one?R
What number has 8 tens and 6 ones?H
0/15 letters found
Clue 5
Missing addends — the last clue
We want nine juice boxes for the whole team. We only have six. How many more juice boxes do we need to find?
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
6 + ___ = 18
10 + ___ = 17
3 + ___ = 12
10 + ___ = 12
8 + ___ = 19
3 + ___ = 13
10 + ___ = 11
5 + ___ = 10
1 + ___ = 9
1 + ___ = 7
4 + ___ = 7
Step 2 — cross out the sentence with each answer
1.The villain climbed up the thick rope, then dropped a green glow stick.
2.The villain slid down the tall tree, then called a friend on a walkie talkie.
3.The villain built a quick wooden bridge, then looked through a tiny spy glass.
4.The villain read the old treasure map, then called a friend on a walkie talkie.
5.The villain read the old treasure map, then dropped a green glow stick.
6.The villain read the old treasure map, then looked through a tiny spy glass.
7.The villain decoded the secret note, then dropped a green glow stick.
8.The villain slid down the tall tree, then looked through a tiny spy glass.
9.The villain slid down the tall tree, then splashed a wet water balloon.
10.The villain decoded the secret note, then called a friend on a walkie talkie.
11.The villain decoded the secret note, then looked through a tiny spy glass.
12.The villain decoded the secret note, then shined a bright laser pointer.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Treehouse Club Caper
Culprit: Zoey (map reading · walkie talkie · wears a blue badge · wavy hair · dislikes itchy grass)
- Clue 1 (Addition): "THE SNEAKY BANDIT DOES NOT USE A SPY GLASS"3 + 2 = 5 (T) · 10 + 7 = 17 (L) · 5 + 8 = 13 (G) · 4 + 10 = 14 (D) · 8 + 8 = 16 (S) · 9 + 6 = 15 (Y) · 5 + 1 = 6 (H) · 9 + 11 = 20 (A) · 6 + 4 = 10 (B) · 6 + 2 = 8 (P) · 11 + 7 = 18 (U) · 7 + 5 = 12 (E) · 8 + 3 = 11 (K) · 3 + 1 = 4 (O) · 4 + 5 = 9 (I) · 1 + 1 = 2 (N)
- Clue 2 (Subtraction): "THE VILLAIN WEARS A BLUE BADGE"11 - 5 = 6 (T) · 20 - 2 = 18 (I) · 13 - 2 = 11 (D) · 12 - 7 = 5 (H) · 18 - 1 = 17 (E) · 18 - 3 = 15 (W) · 12 - 8 = 4 (U) · 19 - 3 = 16 (S) · 10 - 2 = 8 (A) · 4 - 2 = 2 (L) · 14 - 4 = 10 (G) · 20 - 1 = 19 (N) · 15 - 1 = 14 (B) · 17 - 5 = 12 (R) · 8 - 7 = 1 (V)
- Clue 3 (Skip counting): "THE VILLAIN DISLIKES ITCHY GREEN GRASS"Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120 = 100 (T) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, ___, 80, 90 = 70 (G) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, ___, 30, 32 = 28 (R) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, ___, 30, 33 = 27 (Y) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42 = 36 (E) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30 = 26 (A) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, ___, 60, 65 = 55 (V) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100 = 80 (I) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27 = 21 (C) · Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12 = 8 (N) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18 = 14 (D) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14 = 10 (L) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, ___, 14, 16 = 12 (S) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45 = 35 (H) · Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10 = 6 (K)
- Clue 4 (Place value): "WE FOUND WAVY HAIR NEAR THE TREEHOUSE"What number has 9 tens and 0 ones? = 90 (W) · What number has 6 tens and 6 ones? = 66 (E) · What number has 6 tens and 0 ones? = 60 (V) · What number has 2 tens and 8 ones? = 28 (A) · What number has 5 tens and 0 ones? = 50 (T) · What number has 4 tens and 1 one? = 41 (U) · What number has 3 tens and 9 ones? = 39 (Y) · What number has 5 tens and 8 ones? = 58 (S) · What number has 4 tens and 8 ones? = 48 (N) · What number has 9 tens and 1 one? = 91 (O) · What number has 8 tens and 3 ones? = 83 (D) · What number has 8 tens and 0 ones? = 80 (I) · What number has 1 ten and 9 ones? = 19 (F) · What number has 5 tens and 1 one? = 51 (R) · What number has 8 tens and 6 ones? = 86 (H)
- Clue 5 (Missing addends): surviving statement (box 4) → Zoey6 + ___ = 18 = 12 · 10 + ___ = 17 = 7 · 3 + ___ = 12 = 9 · 10 + ___ = 12 = 2 · 8 + ___ = 19 = 11 · 3 + ___ = 13 = 10 · 10 + ___ = 11 = 1 · 5 + ___ = 10 = 5 · 1 + ___ = 9 = 8 · 1 + ___ = 7 = 6 · 4 + ___ = 7 = 3
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Addition, Subtraction, Skip counting, Place value, Missing addends
- Reading level
- grades 1-2
- Theme
- The Treehouse Club Caper — set in Treehouse Island
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects