Grade 10Reading: grades 1-2AdditionRoundingMulti-step word problemsPythagorean theoremSquare roots
The Treehouse Mystery
A sneaky bandit took the golden treehouse key! We must find the bandit and get it back.
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 | Super Tool | Secret Badge | Stepping Foot | Bandana Color | Best Snack |
|---|---|---|---|---|---|
| Toby | grappling hook | wolf badge | left foot first | green bandana | salty cheese |
| Emma | magic compass | owl badge | right foot first | green bandana | crunchy apple |
| Hugo | magic compass | bear badge | left foot first | green bandana | crunchy apple |
| Owen | loud whistle | wolf badge | right foot first | green bandana | sweet cookie |
| Quinn | super flashlight | wolf badge | left foot first | green bandana | crunchy apple |
| Ben | grappling hook | owl badge | right foot first | red bandana | salty cheese |
| Wyatt | super flashlight | wolf badge | right foot first | green bandana | crunchy apple |
| Uma | super flashlight | frog badge | right foot first | green bandana | sweet cookie |
| Noah | shiny spyglass | frog badge | left foot first | green bandana | crunchy apple |
| Zoe | magic compass | bear badge | right foot first | green bandana | crunchy apple |
| Jack | loud whistle | bear badge | left foot first | red bandana | crunchy apple |
| Vince | shiny spyglass | fox badge | right foot first | green bandana | crunchy apple |
| Mia | magic compass | fox badge | right foot first | green bandana | salty cheese |
| Finn | magic compass | owl badge | left foot first | red bandana | crunchy apple |
| Leo | grappling hook | owl badge | left foot first | green bandana | salty cheese |
| Dan | grappling hook | owl badge | right foot first | green bandana | crunchy apple |
| Ruby | grappling hook | fox badge | right foot first | red bandana | sweet cookie |
| Iris | magic compass | bear badge | right foot first | blue bandana | sweet cookie |
| Sam | loud whistle | bear badge | left foot first | blue bandana | salty cheese |
| Gaby | grappling hook | owl badge | right foot first | blue bandana | crunchy apple |
| Kai | loud whistle | owl badge | right foot first | green bandana | sweet cookie |
Clue 1
Addition
We count the gold coins in the dirt. We add them up to find a 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
7394
8118
8787
2856
9048
2795
7706
5091
T
7394
7706
7138
8787
3847
2795
7138
T
7394
5223
8787
9048
8790
T
7394
8118
8787
9324
7138
7333
2856
9048
7706
4029
8787
3067 + 4327 =T
1154 + 1641 =N
2712 + 4621 =X
1859 + 3364 =W
1428 + 2601 =G
1718 + 1138 =B
5139 + 4185 =F
2729 + 4409 =O
5317 + 3473 =R
3701 + 4005 =D
2321 + 1526 =S
4274 + 4774 =A
2937 + 5850 =E
4447 + 3671 =H
1756 + 3335 =I
0/15 letters found
Clue 2
Rounding
Our old scope only shows big rounded numbers. It tells us where the bandit went.
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
3000
2300
290
300
200
200
T
3000
4300
900
50
1700
T
3000
700
T
3000
2900
900
T
3000
700
430
50
T
3000
2300
T
3000
2300
290
900
50
20
2300
T
3000
300
200
200
T
3000
Round 3,381 to the nearest thousandT
Round 22 to the nearest tenG
Round 713 to the nearest hundredS
Round 303 to the nearest hundredF
Round 2,940 to the nearest hundredA
Round 426 to the nearest tenW
Round 287 to the nearest tenE
Round 1,741 to the nearest hundredN
Round 46 to the nearest tenI
Round 2,328 to the nearest hundredH
Round 225 to the nearest hundredO
Round 4,293 to the nearest hundredP
Round 947 to the nearest hundredR
0/13 letters found
Clue 3
Multi-step word problems
We must count boxes of fruit and bags of seeds. Follow the steps to get the next clue.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Someonescaredthevillainoffwith .
C
87
55
8
27
C
87
49
69
66
P
P
L
E
Ranger Pete collected 125 map in the morning and 136 map in the afternoon, then split them equally among 3 The Treehouse Club. How many map did each get?C
There were 210 badge in all. 4 The Treehouse Club used 39 badge each. The other 2 The Treehouse Club shared the rest equally. How many badge did each of the other The Treehouse Club get?N
There were 375 coin in all. 3 The Treehouse Club used 37 coin each. The other 4 The Treehouse Club shared the rest equally. How many coin did each of the other The Treehouse Club get?A
Ranger Pete earned 8 badge in each of 2 rounds, plus 47 bonus badge. Then 14 badge were lost. How many badge are left?H
Ranger Pete collected 8 map in the morning and 8 map in the afternoon, then split them equally among 2 The Treehouse Club. How many map did each get?U
Ranger Pete collected 27 badge in the morning and 111 badge in the afternoon, then split them equally among 2 The Treehouse Club. How many badge did each get?Y
Ranger Pete earned 6 shell in each of 5 rounds, plus 40 bonus shell. Then 15 shell were lost. How many shell are left?R
0/7 letters found
Clue 4
Pythagorean theorem
We look at the map grid. We find the short diagonal path across the field.
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
125
17
58
74
15
25
37
34
123
52
17
17
25
10
65
52
17
34
37
74
25
10
65
17
40
52
34
25
87
65
legs 35 and 120, hypotenuse =W
legs 25 and 60, hypotenuse =H
legs 60 and 63, hypotenuse =C
legs 9 and 12, hypotenuse =U
legs 20 and 48, hypotenuse =R
legs 8 and 15, hypotenuse =E
legs 24 and 32, hypotenuse =B
legs 27 and 120, hypotenuse =G
legs 15 and 20, hypotenuse =N
legs 24 and 70, hypotenuse =O
legs 12 and 35, hypotenuse =D
legs 16 and 30, hypotenuse =A
legs 6 and 8, hypotenuse =T
legs 40 and 42, hypotenuse =F
0/14 letters found
Clue 5
Square roots — the last clue
We find a square room. The size of one wall gives us the last clue.
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
sqrt(49) = ?
sqrt(121) = ?
sqrt(9) = ?
sqrt(16) = ?
sqrt(144) = ?
sqrt(100) = ?
sqrt(64) = ?
sqrt(25) = ?
sqrt(36) = ?
sqrt(1) = ?
sqrt(81) = ?
Step 2 — cross out the sentence with each answer
1.The villain spotted the shiny key, then howled like a wild wolf.
2.The villain lit up the dark path, then howled like a wild wolf.
3.The villain found the secret trail, then hooted like a wise owl.
4.The villain signaled the team, then dashed away like a quick fox.
5.The villain spotted the shiny key, then hooted like a wise owl.
6.The villain lit up the dark path, then dashed away like a quick fox.
7.The villain swung across the trees, then hooted like a wise owl.
8.The villain found the secret trail, then hopped like a little frog.
9.The villain swung across the trees, then howled like a wild wolf.
10.The villain signaled the team, then howled like a wild wolf.
11.The villain found the secret trail, then roared like a giant bear.
12.The villain signaled the team, then hopped like a little frog.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Treehouse Mystery
Culprit: Wyatt (super flashlight · wolf badge · right foot first · green bandana · crunchy apple)
- Clue 1 (Addition): "THE BANDIT DOES NOT WEAR THE FOX BADGE"3067 + 4327 = 7394 (T) · 1154 + 1641 = 2795 (N) · 2712 + 4621 = 7333 (X) · 1859 + 3364 = 5223 (W) · 1428 + 2601 = 4029 (G) · 1718 + 1138 = 2856 (B) · 5139 + 4185 = 9324 (F) · 2729 + 4409 = 7138 (O) · 5317 + 3473 = 8790 (R) · 3701 + 4005 = 7706 (D) · 2321 + 1526 = 3847 (S) · 4274 + 4774 = 9048 (A) · 2937 + 5850 = 8787 (E) · 4447 + 3671 = 8118 (H) · 1756 + 3335 = 5091 (I)
- Clue 2 (Rounding): "THE FOOTPRINT STARTS WITH THE RIGHT FOOT"Round 3,381 to the nearest thousand = 3000 (T) · Round 22 to the nearest ten = 20 (G) · Round 713 to the nearest hundred = 700 (S) · Round 303 to the nearest hundred = 300 (F) · Round 2,940 to the nearest hundred = 2900 (A) · Round 426 to the nearest ten = 430 (W) · Round 287 to the nearest ten = 290 (E) · Round 1,741 to the nearest hundred = 1700 (N) · Round 46 to the nearest ten = 50 (I) · Round 2,328 to the nearest hundred = 2300 (H) · Round 225 to the nearest hundred = 200 (O) · Round 4,293 to the nearest hundred = 4300 (P) · Round 947 to the nearest hundred = 900 (R)
- Clue 3 (Multi-step word problems): "CRUNCHY APPLE"Ranger Pete collected 125 map in the morning and 136 map in the afternoon, then split them equally among 3 The Treehouse Club. How many map did each get? = 87 (C) · There were 210 badge in all. 4 The Treehouse Club used 39 badge each. The other 2 The Treehouse Club shared the rest equally. How many badge did each of the other The Treehouse Club get? = 27 (N) · There were 375 coin in all. 3 The Treehouse Club used 37 coin each. The other 4 The Treehouse Club shared the rest equally. How many coin did each of the other The Treehouse Club get? = 66 (A) · Ranger Pete earned 8 badge in each of 2 rounds, plus 47 bonus badge. Then 14 badge were lost. How many badge are left? = 49 (H) · Ranger Pete collected 8 map in the morning and 8 map in the afternoon, then split them equally among 2 The Treehouse Club. How many map did each get? = 8 (U) · Ranger Pete collected 27 badge in the morning and 111 badge in the afternoon, then split them equally among 2 The Treehouse Club. How many badge did each get? = 69 (Y) · Ranger Pete earned 6 shell in each of 5 rounds, plus 40 bonus shell. Then 15 shell were lost. How many shell are left? = 55 (R)
- Clue 4 (Pythagorean theorem): "WE FOUND A GREEN THREAD ON THE BRANCH"legs 35 and 120, hypotenuse = 125 (W) · legs 25 and 60, hypotenuse = 65 (H) · legs 60 and 63, hypotenuse = 87 (C) · legs 9 and 12, hypotenuse = 15 (U) · legs 20 and 48, hypotenuse = 52 (R) · legs 8 and 15, hypotenuse = 17 (E) · legs 24 and 32, hypotenuse = 40 (B) · legs 27 and 120, hypotenuse = 123 (G) · legs 15 and 20, hypotenuse = 25 (N) · legs 24 and 70, hypotenuse = 74 (O) · legs 12 and 35, hypotenuse = 37 (D) · legs 16 and 30, hypotenuse = 34 (A) · legs 6 and 8, hypotenuse = 10 (T) · legs 40 and 42, hypotenuse = 58 (F)
- Clue 5 (Square roots): surviving statement (box 2) → Wyattsqrt(49) = 7 · sqrt(121) = 11 · sqrt(9) = 3 · sqrt(16) = 4 · sqrt(144) = 12 · sqrt(100) = 10 · sqrt(64) = 8 · sqrt(25) = 5 · sqrt(36) = 6 · sqrt(1) = 1 · sqrt(81) = 9
About this mystery
- Grade level
- Grade 10 math
- Math topics
- Addition, Rounding, Multi-step word problems, Pythagorean theorem, Square roots
- Reading level
- grades 1-2
- Theme
- The Treehouse Mystery — set in Treehouse Island
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects