Grade 2Reading: grades 3-4AdditionRoundingSkip countingPlace valueMissing addends
The Golden Idol of Mist Cove
Someone snuck into the ancient Sun Temple on Mist Cove Island and took the Golden Idol! Clues were left behind along the trail. Help the expedition crew decode the clues and identify the bandit before they leave the island.
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 | Expedition Tool | Secret Device | Watch Wrist | Bandana Color | Trap Vulnerability |
|---|---|---|---|---|---|
| Pilot Max | Lantern | Mini Submarine | Right Wrist Watch | Blue Bandana | Net Launcher |
| Agent Zoe | Signal Flare | Mini Submarine | Left Wrist Watch | Green Bandana | Mud Pit |
| Tracker Rex | Machete | Smoke Bomb | Left Wrist Watch | Blue Bandana | Net Launcher |
| Searcher Cole | Machete | Magnet Glove | Right Wrist Watch | Red Bandana | Snare Trap |
| Captain Leo | Lantern | Mini Submarine | Left Wrist Watch | Blue Bandana | Net Launcher |
| Officer Ben | Machete | Echo Locator | Right Wrist Watch | Green Bandana | Net Launcher |
| Tracker Zac | Machete | Magnet Glove | Right Wrist Watch | Blue Bandana | Net Launcher |
| Professor Oak | Signal Flare | Smoke Bomb | Left Wrist Watch | Green Bandana | Net Launcher |
| Climber Mia | Compass | Mini Submarine | Right Wrist Watch | Green Bandana | Net Launcher |
| Scout Nora | Signal Flare | Echo Locator | Left Wrist Watch | Blue Bandana | Mud Pit |
| Ranger Owen | Signal Flare | Mini Submarine | Right Wrist Watch | Red Bandana | Snare Trap |
| Guide Kai | Machete | Magnet Glove | Left Wrist Watch | Red Bandana | Snare Trap |
| Guide Amy | Machete | Magnet Glove | Right Wrist Watch | Green Bandana | Mud Pit |
| Dr Lily | Machete | Echo Locator | Right Wrist Watch | Red Bandana | Net Launcher |
| Diver Ian | Signal Flare | Glider Pack | Left Wrist Watch | Green Bandana | Mud Pit |
| Botanist Ivy | Machete | Smoke Bomb | Right Wrist Watch | Green Bandana | Net Launcher |
| Trekker Finn | Machete | Mini Submarine | Left Wrist Watch | Red Bandana | Mud Pit |
| Explorer Jade | Grappling Hook | Magnet Glove | Right Wrist Watch | Green Bandana | Net Launcher |
| Surveyor Ruby | Machete | Echo Locator | Left Wrist Watch | Green Bandana | Net Launcher |
| Explorer Maya | Signal Flare | Magnet Glove | Right Wrist Watch | Green Bandana | Net Launcher |
| Navigator Eva | Signal Flare | Magnet Glove | Left Wrist Watch | Green Bandana | Snare Trap |
Clue 1
Addition
We tallied all the coconut supplies gathered by the team today.
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
78
51
39
71
23
64
64
98
23
40
85
23
85
40
91
T
78
33
52
39
98
58
23
40
23
52
33
66
58
98
77
23
40
39
46 + 32 =T
26 + 13 =E
22 + 30 =S
13 + 10 =I
29 + 37 =B
24 + 9 =U
64 + 27 =O
54 + 31 =D
17 + 23 =N
32 + 66 =A
28 + 36 =L
40 + 31 =V
18 + 40 =M
25 + 26 =H
51 + 26 =R
0/15 letters found
Clue 2
Rounding
The digital island radar only shows whole estimated mile markers.
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
200
500
40
90
30
90
20
40
600
T
200
700
40
50
400
90
50
700
50
T
200
600
500
800
900
T
200
500
40
400
70
60
500
T
200
700
400
70
90
T
200
Round 159 to the nearest hundredT
Round 625 to the nearest hundredC
Round 928 to the nearest hundredN
Round 68 to the nearest tenI
Round 24 to the nearest tenP
Round 39 to the nearest tenE
Round 47 to the nearest tenA
Round 34 to the nearest tenU
Round 90 to the nearest tenS
Round 775 to the nearest hundredO
Round 416 to the nearest hundredR
Round 513 to the nearest hundredH
Round 683 to the nearest hundredW
Round 57 to the nearest tenG
0/14 letters found
Clue 3
Skip counting
We counted the ancient carved stone steps by twos up the hill.
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
26
12
8
15
6
6
22
15
25
42
22
35
27
22
70
36
26
T
10
90
120
22
25
12
T
10
6
22
70
25
27
26
12
65
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14T
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21I
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75R
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140Y
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, ___, 30, 33C
Skip-count by 3s. Fill the blank: 3, 6, 9, ___, 15, 18E
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, ___, 24, 26A
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48W
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35N
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80U
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110B
Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10L
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45S
Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12V
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30H
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42G
0/16 letters found
Clue 4
Place value
The temple door puzzle requires building a number with 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
70
18
64
51
51
77
43
A
70
77
12
A
70
77
A
70
68
A
70
82
82
87
64
63
59
59
51
12
43
39
A
70
87
64
51
51
43
64
A
70
77
40
85
What number has 7 tens and 0 ones?A
What number has 6 tens and 4 ones?R
What number has 5 tens and 9 ones?P
What number has 1 ten and 8 ones?G
What number has 8 tens and 7 ones?T
What number has 3 tens and 9 ones?Y
What number has 8 tens and 2 ones?S
What number has 1 ten and 2 ones?D
What number has 4 tens and 0 ones?C
What number has 4 tens and 3 ones?B
What number has 6 tens and 3 ones?I
What number has 7 tens and 7 ones?N
What number has 5 tens and 1 one?E
What number has 8 tens and 5 ones?H
What number has 6 tens and 8 ones?W
0/15 letters found
Clue 5
Missing addends — the last clue
We found a partial list of golden coins and need to find what is missing.
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
2 + ___ = 6
10 + ___ = 21
2 + ___ = 8
3 + ___ = 15
4 + ___ = 14
10 + ___ = 19
1 + ___ = 8
8 + ___ = 9
10 + ___ = 12
1 + ___ = 9
8 + ___ = 11
Step 2 — cross out the sentence with each answer
1.The villain used a machete to cut vines, then escaped underwater with a mini submarine.
2.The villain fired a signal flare into the sky, then escaped underwater with a mini submarine.
3.The villain lit up the cave with a lantern, then mapped the cave using an echo locator.
4.The villain used a machete to cut vines, then dropped a smoke bomb to vanish.
5.The villain used a machete to cut vines, then mapped the cave using an echo locator.
6.The villain swung across the gap with a grappling hook, then snatched the gold with a magnet glove.
7.The villain fired a signal flare into the sky, then mapped the cave using an echo locator.
8.The villain swung across the gap with a grappling hook, then dropped a smoke bomb to vanish.
9.The villain lit up the cave with a lantern, then dropped a smoke bomb to vanish.
10.The villain checked the ancient compass, then mapped the cave using an echo locator.
11.The villain fired a signal flare into the sky, then snatched the gold with a magnet glove.
12.The villain used a machete to cut vines, then snatched the gold with a magnet glove.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Golden Idol of Mist Cove
Culprit: Officer Ben (Machete · Echo Locator · Right Wrist Watch · Green Bandana · Net Launcher)
- Clue 1 (Addition): "THE VILLAIN DID NOT USE A MINI SUBMARINE"46 + 32 = 78 (T) · 26 + 13 = 39 (E) · 22 + 30 = 52 (S) · 13 + 10 = 23 (I) · 29 + 37 = 66 (B) · 24 + 9 = 33 (U) · 64 + 27 = 91 (O) · 54 + 31 = 85 (D) · 17 + 23 = 40 (N) · 32 + 66 = 98 (A) · 28 + 36 = 64 (L) · 40 + 31 = 71 (V) · 18 + 40 = 58 (M) · 25 + 26 = 51 (H) · 51 + 26 = 77 (R)
- Clue 2 (Rounding): "THE SUSPECT WEARS A WATCH ON THE RIGHT WRIST"Round 159 to the nearest hundred = 200 (T) · Round 625 to the nearest hundred = 600 (C) · Round 928 to the nearest hundred = 900 (N) · Round 68 to the nearest ten = 70 (I) · Round 24 to the nearest ten = 20 (P) · Round 39 to the nearest ten = 40 (E) · Round 47 to the nearest ten = 50 (A) · Round 34 to the nearest ten = 30 (U) · Round 90 to the nearest ten = 90 (S) · Round 775 to the nearest hundred = 800 (O) · Round 416 to the nearest hundred = 400 (R) · Round 513 to the nearest hundred = 500 (H) · Round 683 to the nearest hundred = 700 (W) · Round 57 to the nearest ten = 60 (G)
- Clue 3 (Skip counting): "THE VILLAIN WAS CAUGHT BY A NET LAUNCHER"Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14 = 10 (T) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21 = 15 (I) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75 = 65 (R) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140 = 120 (Y) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, ___, 30, 33 = 27 (C) · Skip-count by 3s. Fill the blank: 3, 6, 9, ___, 15, 18 = 12 (E) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, ___, 24, 26 = 22 (A) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48 = 42 (W) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35 = 25 (N) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80 = 70 (U) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110 = 90 (B) · Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10 = 6 (L) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45 = 35 (S) · Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12 = 8 (V) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30 = 26 (H) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42 = 36 (G)
- Clue 4 (Place value): "A GREEN BANDANA WAS STRIPPED BY A TREE BRANCH"What number has 7 tens and 0 ones? = 70 (A) · What number has 6 tens and 4 ones? = 64 (R) · What number has 5 tens and 9 ones? = 59 (P) · What number has 1 ten and 8 ones? = 18 (G) · What number has 8 tens and 7 ones? = 87 (T) · What number has 3 tens and 9 ones? = 39 (Y) · What number has 8 tens and 2 ones? = 82 (S) · What number has 1 ten and 2 ones? = 12 (D) · What number has 4 tens and 0 ones? = 40 (C) · What number has 4 tens and 3 ones? = 43 (B) · What number has 6 tens and 3 ones? = 63 (I) · What number has 7 tens and 7 ones? = 77 (N) · What number has 5 tens and 1 one? = 51 (E) · What number has 8 tens and 5 ones? = 85 (H) · What number has 6 tens and 8 ones? = 68 (W)
- Clue 5 (Missing addends): surviving statement (box 5) → Officer Ben2 + ___ = 6 = 4 · 10 + ___ = 21 = 11 · 2 + ___ = 8 = 6 · 3 + ___ = 15 = 12 · 4 + ___ = 14 = 10 · 10 + ___ = 19 = 9 · 1 + ___ = 8 = 7 · 8 + ___ = 9 = 1 · 10 + ___ = 12 = 2 · 1 + ___ = 9 = 8 · 8 + ___ = 11 = 3
About this mystery
- Grade level
- Grade 2 math
- Math topics
- Addition, Rounding, Skip counting, Place value, Missing addends
- Reading level
- grades 3-4
- Theme
- The Golden Idol of Mist Cove — set in Mist Cove Island
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects