Grade 7Reading: grades 3-4Place valueSkip countingRoundingBar modelsTwo-step equations
The Secret of Whispering Vine Island
The Chief Explorer's golden compass has vanished from the jungle camp! The Jungle Bandit sneaked in under the cover of night. Now, we must search the ancient ruins and track down the culprit.
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 | Jungle Skill | Camp Gear | Compass Side | Headwear | Fear or Flaw |
|---|---|---|---|---|---|
| Nathan | river rafting | rope tying | left-handed compass | blue safari helmet | scared of frogs |
| Indiana | cave diving | rope tying | right-handed compass | blue safari helmet | afraid of heights |
| Gemma | cave diving | animal whispering | right-handed compass | red explorer hat | scared of frogs |
| Toby | cave diving | animal whispering | right-handed compass | green camo bandana | allergic to pollen |
| Zoe | vine swinging | rope tying | right-handed compass | green camo bandana | allergic to pollen |
| Zack | river rafting | animal whispering | right-handed compass | blue safari helmet | afraid of heights |
| Maya | quick climbing | jungle camouflage | right-handed compass | green camo bandana | allergic to pollen |
| Claire | quick climbing | torch lighting | left-handed compass | green camo bandana | scared of frogs |
| Diego | river rafting | jungle camouflage | right-handed compass | green camo bandana | allergic to pollen |
| Finn | river rafting | torch lighting | right-handed compass | green camo bandana | allergic to pollen |
| Leo | map reading | torch lighting | left-handed compass | red explorer hat | afraid of heights |
| Skye | river rafting | animal whispering | right-handed compass | blue safari helmet | allergic to pollen |
| Alex | cave diving | animal whispering | right-handed compass | green camo bandana | scared of frogs |
| Chloe | river rafting | bridge building | left-handed compass | green camo bandana | allergic to pollen |
| Penny | river rafting | torch lighting | left-handed compass | red explorer hat | afraid of heights |
| Rusty | map reading | jungle camouflage | left-handed compass | blue safari helmet | allergic to pollen |
| Brooke | quick climbing | torch lighting | right-handed compass | blue safari helmet | afraid of heights |
| Sully | cave diving | jungle camouflage | right-handed compass | red explorer hat | allergic to pollen |
| Max | vine swinging | rope tying | right-handed compass | red explorer hat | allergic to pollen |
| Dora | vine swinging | jungle camouflage | right-handed compass | blue safari helmet | scared of frogs |
| Sam | cave diving | torch lighting | left-handed compass | blue safari helmet | scared of frogs |
Clue 1
Place value
We found a dusty digital lock on the temple door. The screen shows a number with the digit four in the tens place.
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
600
800
9000
2000
7000
200
50
5000
T
600
50
300
9000
3000
200
300
T
600
70
3000
9000
4000
300
30
9000
T
600
6000
5000
200
10
What is the value of the 6 in 725,650?T
What is the value of the 1 in 95,615?G
What is the value of the 3 in 13,278?S
What is the value of the 5 in 95,626?I
What is the value of the 7 in 158,479?U
What is the value of the 3 in 791,538?P
What is the value of the 2 in 32,799?B
What is the value of the 2 in 700,274?N
What is the value of the 6 in 26,938?Y
What is the value of the 5 in 477,252?D
What is the value of the 3 in 99,385?O
What is the value of the 4 in 14,960?R
What is the value of the 9 in 859,341?E
What is the value of the 8 in 266,839?H
What is the value of the 7 in 667,114?A
0/15 letters found
Clue 2
Skip counting
To track the bandit, we count the muddy footprints leading into the swamp. They are spaced out in steady groups of seven.
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
120
40
80
16
26
90
18
110
70
70
130
110
70
33
36
26
18
18
80
33
26
15
T
120
40
80
36
50
39
40
T
120
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140T
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, ___, 20, 22P
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100E
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110M
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150W
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, ___, 45, 50H
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45G
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, ___, 60, 70I
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, ___, 36, 39D
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20C
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42R
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30O
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21N
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80S
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130A
0/15 letters found
Clue 3
Rounding
The camp radio crackles with a signal. The signal strength dial only shows the nearest hundred to help us locate the source.
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
500
1700
290
130
W
500
5000
2000
1700
200
290
7000
1700
1700
20
4300
7000
300
90
3000
5000
2000
1700
900
50
170
W
500
1700
110
290
Round 517 to the nearest hundredW
Round 86 to the nearest tenB
Round 171 to the nearest tenO
Round 3,389 to the nearest thousandY
Round 169 to the nearest hundredM
Round 267 to the nearest hundredG
Round 4,307 to the nearest hundredI
Round 114 to the nearest tenR
Round 53 to the nearest tenL
Round 127 to the nearest tenA
Round 22 to the nearest tenZ
Round 2,409 to the nearest thousandH
Round 904 to the nearest hundredF
Round 7,367 to the nearest thousandN
Round 1,708 to the nearest hundredE
Round 4,636 to the nearest thousandT
Round 291 to the nearest tenS
0/17 letters found
Clue 4
Bar model word problems
We compare the lengths of the broken vines near the camp. We draw tape diagrams to see which path is the longest.
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.
Astrandof hairturnedupatthescene.
G
89
97
40
40
8
137
143
118
O
B
143
8
D
143
8
143
The red team has 113 flashlights and the blue team has 24 flashlights. How many more flashlights does the red team have?
draw a bar model
Answer:→G
The red team has 160 gold coins and the blue team has 23 gold coins. How many more gold coins does the red team have?
draw a bar model
Answer:→C
The Lead Scout used 1/2 of the flashlights on the first day. The other 59 flashlights were used the next day. How many flashlights were there in all?
draw a bar model
Answer:→M
There were 182 banana snacks in all. 39 banana snacks were used. How many banana snacks are left?
draw a bar model
Answer:→A
One group collected 29 gold coins and another group collected 11 gold coins. How many gold coins in all?
draw a bar model
Answer:→E
One group collected 93 banana snacks and another group collected 4 banana snacks. How many banana snacks in all?
draw a bar model
Answer:→R
There were 27 banana snacks in all. 19 banana snacks were used. How many banana snacks are left?
draw a bar model
Answer:→N
0/7 letters found
Clue 5
Two-step equations — the last clue
A locked supply chest has a puzzle. We must double our gold coins and then add five to find the code.
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
2x + 7 = 9, x = ?
4x + 3 = 35, x = ?
2x + 7 = 11, x = ?
3x + 9 = 27, x = ?
4x + 5 = 17, x = ?
6x + 4 = 76, x = ?
5x + 9 = 64, x = ?
3x + 2 = 29, x = ?
4x + 3 = 31, x = ?
4x + 2 = 22, x = ?
4x + 12 = 52, x = ?
Step 2 — cross out the sentence with each answer
1.The villain paddles down the rushing river, then lights a bright wooden torch.
2.The villain climbs up the slippery cliff, then hides in the thick green ferns.
3.The villain swings across the deep canyon, then builds a bridge over the mud.
4.The villain dives into the glowing blue cave, then whispers to the sleepy monkeys.
5.The villain climbs up the slippery cliff, then lights a bright wooden torch.
6.The villain follows the dusty trail map, then ties a double knot on the tent.
7.The villain dives into the glowing blue cave, then builds a bridge over the mud.
8.The villain paddles down the rushing river, then hides in the thick green ferns.
9.The villain swings across the deep canyon, then lights a bright wooden torch.
10.The villain dives into the glowing blue cave, then hides in the thick green ferns.
11.The villain climbs up the slippery cliff, then whispers to the sleepy monkeys.
12.The villain paddles down the rushing river, then builds a bridge over the mud.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Secret of Whispering Vine Island
Culprit: Toby (cave diving · animal whispering · right-handed compass · green camo bandana · allergic to pollen)
- Clue 1 (Place value): "THE BANDIT DOES NOT USE ROPE TYING"What is the value of the 6 in 725,650? = 600 (T) · What is the value of the 1 in 95,615? = 10 (G) · What is the value of the 3 in 13,278? = 3000 (S) · What is the value of the 5 in 95,626? = 5000 (I) · What is the value of the 7 in 158,479? = 70 (U) · What is the value of the 3 in 791,538? = 30 (P) · What is the value of the 2 in 32,799? = 2000 (B) · What is the value of the 2 in 700,274? = 200 (N) · What is the value of the 6 in 26,938? = 6000 (Y) · What is the value of the 5 in 477,252? = 50 (D) · What is the value of the 3 in 99,385? = 300 (O) · What is the value of the 4 in 14,960? = 4000 (R) · What is the value of the 9 in 859,341? = 9000 (E) · What is the value of the 8 in 266,839? = 800 (H) · What is the value of the 7 in 667,114? = 7000 (A)
- Clue 2 (Skip counting): "THE COMPASS WAS DROPPED ON THE RIGHT"Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140 = 120 (T) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, ___, 20, 22 = 18 (P) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100 = 80 (E) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110 = 90 (M) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150 = 130 (W) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, ___, 45, 50 = 40 (H) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, ___, 42, 45 = 39 (G) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, ___, 60, 70 = 50 (I) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, ___, 36, 39 = 33 (D) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20 = 16 (C) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42 = 36 (R) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30 = 26 (O) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21 = 15 (N) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80 = 70 (S) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130 = 110 (A)
- Clue 3 (Rounding): "WE SAW THEM SNEEZING BY THE FLOWERS"Round 517 to the nearest hundred = 500 (W) · Round 86 to the nearest ten = 90 (B) · Round 171 to the nearest ten = 170 (O) · Round 3,389 to the nearest thousand = 3000 (Y) · Round 169 to the nearest hundred = 200 (M) · Round 267 to the nearest hundred = 300 (G) · Round 4,307 to the nearest hundred = 4300 (I) · Round 114 to the nearest ten = 110 (R) · Round 53 to the nearest ten = 50 (L) · Round 127 to the nearest ten = 130 (A) · Round 22 to the nearest ten = 20 (Z) · Round 2,409 to the nearest thousand = 2000 (H) · Round 904 to the nearest hundred = 900 (F) · Round 7,367 to the nearest thousand = 7000 (N) · Round 1,708 to the nearest hundred = 1700 (E) · Round 4,636 to the nearest thousand = 5000 (T) · Round 291 to the nearest ten = 290 (S)
- Clue 4 (Bar model word problems): "GREEN CAMO BANDANA"The red team has 113 flashlights and the blue team has 24 flashlights. How many more flashlights does the red team have? = 89 (G) · The red team has 160 gold coins and the blue team has 23 gold coins. How many more gold coins does the red team have? = 137 (C) · The Lead Scout used 1/2 of the flashlights on the first day. The other 59 flashlights were used the next day. How many flashlights were there in all? = 118 (M) · There were 182 banana snacks in all. 39 banana snacks were used. How many banana snacks are left? = 143 (A) · One group collected 29 gold coins and another group collected 11 gold coins. How many gold coins in all? = 40 (E) · One group collected 93 banana snacks and another group collected 4 banana snacks. How many banana snacks in all? = 97 (R) · There were 27 banana snacks in all. 19 banana snacks were used. How many banana snacks are left? = 8 (N)
- Clue 5 (Two-step equations): surviving statement (box 4) → Toby2x + 7 = 9, x = 1 · 4x + 3 = 35, x = 8 · 2x + 7 = 11, x = 2 · 3x + 9 = 27, x = 6 · 4x + 5 = 17, x = 3 · 6x + 4 = 76, x = 12 · 5x + 9 = 64, x = 11 · 3x + 2 = 29, x = 9 · 4x + 3 = 31, x = 7 · 4x + 2 = 22, x = 5 · 4x + 12 = 52, x = 10
About this mystery
- Grade level
- Grade 7 math
- Math topics
- Place value, Skip counting, Rounding, Bar models, Two-step equations
- Reading level
- grades 3-4
- Theme
- The Secret of Whispering Vine Island — set in The Lost Jungle of Whispering Vines
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects