Grade 2Reading: grades 1-2AdditionSkip countingBar modelsPlace valueMissing addends
The Great Treehouse Mystery
Someone took the golden compass from the big treehouse! The camp leader needs your help. Look for clues to find the sneaky map 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 | favorite tool | badge color | holding hand | hat color | scared of |
|---|---|---|---|---|---|
| Abby | pocket flashlight | yellow badge | right handed | blue hat | fake spiders |
| Ruby | magnifying glass | blue badge | left handed | green hat | fake spiders |
| Leo | mini binoculars | green badge | right handed | blue hat | loud whistles |
| Owen | pocket flashlight | blue badge | left handed | blue hat | fake spiders |
| Oliver | pocket flashlight | blue badge | right handed | green hat | muddy puddles |
| Hazel | mini binoculars | orange badge | right handed | blue hat | loud whistles |
| Max | mini binoculars | orange badge | right handed | blue hat | fake spiders |
| Mason | toy walkie talkie | orange badge | left handed | red hat | fake spiders |
| Luke | mini binoculars | blue badge | right handed | red hat | fake spiders |
| Sam | pocket flashlight | blue badge | right handed | blue hat | loud whistles |
| Zoe | toy walkie talkie | orange badge | right handed | green hat | muddy puddles |
| Grace | pocket flashlight | red badge | left handed | green hat | fake spiders |
| Mia | magnifying glass | blue badge | right handed | blue hat | fake spiders |
| Ella | mini binoculars | blue badge | left handed | red hat | muddy puddles |
| Jake | magnifying glass | green badge | right handed | blue hat | fake spiders |
| Ben | toy walkie talkie | orange badge | right handed | green hat | loud whistles |
| Carter | mini binoculars | green badge | left handed | green hat | muddy puddles |
| Sophia | toy walkie talkie | green badge | right handed | blue hat | fake spiders |
| Emma | pocket flashlight | blue badge | left handed | red hat | fake spiders |
| Toby | mini binoculars | orange badge | right handed | red hat | loud whistles |
| Lily | mini binoculars | green badge | left handed | blue hat | muddy puddles |
Clue 1
Addition
We count the trail markers on the path. Let us add them up to find the first clue.
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
84
82
39
T
84
82
43
39
22
24
49
39
21
47
49
T
84
94
39
88
28
T
84
82
39
49
28
88
47
57
39
65
88
24
57
39
33 + 51 =T
41 + 41 =H
9 + 12 =S
43 + 22 =B
17 + 7 =D
63 + 31 =W
23 + 24 =N
37 + 20 =G
15 + 13 =R
44 + 44 =A
11 + 11 =F
32 + 17 =O
22 + 17 =E
28 + 15 =I
0/14 letters found
Clue 2
Skip counting
We jump along the numbered logs. Let us count by twos to read the sign.
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
39
50
21
15
14
6
T
39
22
16
35
35
T
39
70
90
65
80
T
39
6
120
21
36
80
21
15
T
39
35
T
39
50
21
90
65
110
50
T
39
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45T
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110R
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18U
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45O
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75I
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20F
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140L
Skip-count by 5s. Fill the blank: 5, 10, ___, 20, 25D
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130G
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, ___, 24, 26Y
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80P
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42A
Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10S
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100N
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27E
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, ___, 60, 70H
0/16 letters found
Clue 3
Bar model word problems
The ropes have different lengths. We can compare them side by side to see a hint.
Draw a bar model to solve each word problem. Its answer reveals a letter — write the letters in the boxes to fill in the missing word.
Someonescaredthevillainoffwith .
F
33
46
28
44
56
19
13
D
44
R
56
The red team has 34 trail snacks and the blue team has 1 trail snacks. How many more trail snacks does the red team have?
draw a bar model
Answer:→F
The red team has 56 shiny acorns and the blue team has 12 shiny acorns. How many more shiny acorns does the red team have?
draw a bar model
Answer:→E
There were 36 shiny acorns in all. 8 shiny acorns were used. How many shiny acorns are left?
draw a bar model
Answer:→K
There were 22 trail snacks in all. 9 trail snacks were used. How many trail snacks are left?
draw a bar model
Answer:→I
One group collected 13 pine cones and another group collected 6 pine cones. How many pine cones in all?
draw a bar model
Answer:→P
One group collected 43 toy binoculars and another group collected 13 toy binoculars. How many toy binoculars in all?
draw a bar model
Answer:→S
There were 52 pine cones in all. 6 pine cones were used. How many pine cones are left?
draw a bar model
Answer:→A
0/7 letters found
Clue 4
Place value
We find a lock box with two digit wheels. We need to check the tens and ones.
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
33
46
88
25
59
64
17
46
19
50
67
17
64
88
67
A
33
89
98
A
33
30
78
55
17
64
67
46
88
A
33
55
90
64
What number has 3 tens and 3 ones?A
What number has 1 ten and 9 ones?L
What number has 1 ten and 7 ones?T
What number has 6 tens and 4 ones?H
What number has 7 tens and 8 ones?O
What number has 9 tens and 8 ones?W
What number has 5 tens and 9 ones?G
What number has 5 tens and 0 ones?U
What number has 9 tens and 0 ones?C
What number has 6 tens and 7 ones?E
What number has 3 tens and 0 ones?S
What number has 5 tens and 5 ones?N
What number has 2 tens and 5 ones?I
What number has 8 tens and 8 ones?R
What number has 4 tens and 6 ones?B
What number has 8 tens and 9 ones?D
0/16 letters found
Clue 5
Missing addends — the last clue
Some map pieces are missing. We must find the missing parts to solve the mystery.
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
5 + ___ = 6
2 + ___ = 10
8 + ___ = 10
2 + ___ = 6
1 + ___ = 7
2 + ___ = 9
6 + ___ = 15
3 + ___ = 6
8 + ___ = 19
3 + ___ = 13
5 + ___ = 10
Step 2 — cross out the sentence with each answer
1.The villain climbed up the rope ladder, then ducked under the picnic table.
2.The villain slid down the zip line, then escaped toward the secret cave.
3.The villain climbed up the rope ladder, then jumped into the big sandbox.
4.The villain crept across the wooden bridge, then escaped toward the secret cave.
5.The villain slid down the zip line, then hid behind the giant oak tree.
6.The villain hopped over the stepping stones, then hid behind the giant oak tree.
7.The villain crept across the wooden bridge, then jumped into the big sandbox.
8.The villain climbed up the rope ladder, then ran into the leafy bushes.
9.The villain hopped over the stepping stones, then ducked under the picnic table.
10.The villain sneaked past the main gate, then jumped into the big sandbox.
11.The villain crept across the wooden bridge, then ran into the leafy bushes.
12.The villain crept across the wooden bridge, then ducked under the picnic table.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Great Treehouse Mystery
Culprit: Sophia (toy walkie talkie · green badge · right handed · blue hat · fake spiders)
- Clue 1 (Addition): "THE THIEF DOES NOT WEAR THE ORANGE BADGE"33 + 51 = 84 (T) · 41 + 41 = 82 (H) · 9 + 12 = 21 (S) · 43 + 22 = 65 (B) · 17 + 7 = 24 (D) · 63 + 31 = 94 (W) · 23 + 24 = 47 (N) · 37 + 20 = 57 (G) · 15 + 13 = 28 (R) · 44 + 44 = 88 (A) · 11 + 11 = 22 (F) · 32 + 17 = 49 (O) · 22 + 17 = 39 (E) · 28 + 15 = 43 (I)
- Clue 2 (Skip counting): "THE DUSTY FOOTPRINTS LEANED TO THE RIGHT"Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45 = 39 (T) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110 = 90 (R) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18 = 14 (U) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45 = 35 (O) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75 = 65 (I) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20 = 16 (F) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140 = 120 (L) · Skip-count by 5s. Fill the blank: 5, 10, ___, 20, 25 = 15 (D) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130 = 110 (G) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, ___, 24, 26 = 22 (Y) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80 = 70 (P) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42 = 36 (A) · Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10 = 6 (S) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100 = 80 (N) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27 = 21 (E) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, ___, 60, 70 = 50 (H)
- Clue 3 (Bar model word problems): "FAKE SPIDERS"The red team has 34 trail snacks and the blue team has 1 trail snacks. How many more trail snacks does the red team have? = 33 (F) · The red team has 56 shiny acorns and the blue team has 12 shiny acorns. How many more shiny acorns does the red team have? = 44 (E) · There were 36 shiny acorns in all. 8 shiny acorns were used. How many shiny acorns are left? = 28 (K) · There were 22 trail snacks in all. 9 trail snacks were used. How many trail snacks are left? = 13 (I) · One group collected 13 pine cones and another group collected 6 pine cones. How many pine cones in all? = 19 (P) · One group collected 43 toy binoculars and another group collected 13 toy binoculars. How many toy binoculars in all? = 56 (S) · There were 52 pine cones in all. 6 pine cones were used. How many pine cones are left? = 46 (A)
- Clue 4 (Place value): "A BRIGHT BLUE THREAD WAS ON THE BRANCH"What number has 3 tens and 3 ones? = 33 (A) · What number has 1 ten and 9 ones? = 19 (L) · What number has 1 ten and 7 ones? = 17 (T) · What number has 6 tens and 4 ones? = 64 (H) · What number has 7 tens and 8 ones? = 78 (O) · What number has 9 tens and 8 ones? = 98 (W) · What number has 5 tens and 9 ones? = 59 (G) · What number has 5 tens and 0 ones? = 50 (U) · What number has 9 tens and 0 ones? = 90 (C) · What number has 6 tens and 7 ones? = 67 (E) · What number has 3 tens and 0 ones? = 30 (S) · What number has 5 tens and 5 ones? = 55 (N) · What number has 2 tens and 5 ones? = 25 (I) · What number has 8 tens and 8 ones? = 88 (R) · What number has 4 tens and 6 ones? = 46 (B) · What number has 8 tens and 9 ones? = 89 (D)
- Clue 5 (Missing addends): surviving statement (box 12) → Sophia5 + ___ = 6 = 1 · 2 + ___ = 10 = 8 · 8 + ___ = 10 = 2 · 2 + ___ = 6 = 4 · 1 + ___ = 7 = 6 · 2 + ___ = 9 = 7 · 6 + ___ = 15 = 9 · 3 + ___ = 6 = 3 · 8 + ___ = 19 = 11 · 3 + ___ = 13 = 10 · 5 + ___ = 10 = 5
About this mystery
- Grade level
- Grade 2 math
- Math topics
- Addition, Skip counting, Bar models, Place value, Missing addends
- Reading level
- grades 1-2
- Theme
- The Great Treehouse Mystery — set in The Great Treehouse Camp
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects