🌊 MermaidsGrade 2Reading: grades 1-2Place valueWord problemsAdditionSubtractionMissing addends
The Mystery of the Coral Cove Pearl
The shiny Star Pearl is missing from Coral Cove! A sneaky sea-thief took it. We must find the thief and save the reef!
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 | Sea Magic | Reef Skill | Waving Style | Hair Accessory | Fear |
|---|---|---|---|---|---|
| Jewel | makes giant bubbles | grows kelp shields | uses right hand to wave | pink sea-shell crown | scared of tickly seaweed |
| Nixie | makes giant bubbles | finds shiny coins | uses left hand to wave | pink sea-shell crown | scared of tickly seaweed |
| Splash | swims super fast | sings sleepy tunes | uses right hand to wave | blue kelp ribbon | scared of noisy gulls |
| Tide | glows in the dark | spins sand whirlpools | uses left hand to wave | pink sea-shell crown | scared of bright flashlights |
| Stormy | swims super fast | grows kelp shields | uses right hand to wave | pink sea-shell crown | scared of tickly seaweed |
| Blue | glows in the dark | sings sleepy tunes | uses right hand to wave | blue kelp ribbon | scared of noisy gulls |
| Sunny | glows in the dark | spins sand whirlpools | uses right hand to wave | blue kelp ribbon | scared of noisy gulls |
| Opal | freezes water | finds shiny coins | uses left hand to wave | pink sea-shell crown | scared of bright flashlights |
| Wave | freezes water | spins sand whirlpools | uses left hand to wave | yellow starfish clip | scared of tickly seaweed |
| Bubbles | glows in the dark | finds shiny coins | uses left hand to wave | blue kelp ribbon | scared of noisy gulls |
| Ocean | talks to whales | summons baby crabs | uses left hand to wave | pink sea-shell crown | scared of tickly seaweed |
| Marina | makes giant bubbles | sings sleepy tunes | uses left hand to wave | pink sea-shell crown | scared of noisy gulls |
| Misty | freezes water | finds shiny coins | uses right hand to wave | pink sea-shell crown | scared of bright flashlights |
| Pearl | makes giant bubbles | grows kelp shields | uses left hand to wave | yellow starfish clip | scared of tickly seaweed |
| Finn | swims super fast | finds shiny coins | uses left hand to wave | pink sea-shell crown | scared of tickly seaweed |
| Star | swims super fast | summons baby crabs | uses left hand to wave | pink sea-shell crown | scared of tickly seaweed |
| Sandy | glows in the dark | sings sleepy tunes | uses right hand to wave | pink sea-shell crown | scared of tickly seaweed |
| Shimmer | swims super fast | finds shiny coins | uses right hand to wave | yellow starfish clip | scared of tickly seaweed |
| River | freezes water | summons baby crabs | uses left hand to wave | blue kelp ribbon | scared of noisy gulls |
| Shelly | swims super fast | grows kelp shields | uses left hand to wave | yellow starfish clip | scared of bright flashlights |
| Aqua | glows in the dark | sings sleepy tunes | uses left hand to wave | pink sea-shell crown | scared of tickly seaweed |
Clue 1
Place value
We need to count the stolen pearls. Let us solve these quick stories to find our first big 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
66
67
36
T
66
67
19
36
56
64
51
36
33
35
51
T
66
33
19
35
82
33
61
36
36
73
45
T
66
38
35
36
33
What number has 6 tens and 6 ones?T
What number has 8 tens and 2 ones?G
What number has 3 tens and 3 ones?S
What number has 7 tens and 3 ones?P
What number has 5 tens and 6 ones?F
What number has 6 tens and 4 ones?D
What number has 3 tens and 6 ones?E
What number has 1 ten and 9 ones?I
What number has 3 tens and 8 ones?U
What number has 4 tens and 5 ones?Y
What number has 6 tens and 1 one?L
What number has 3 tens and 5 ones?N
What number has 5 tens and 1 one?O
What number has 6 tens and 7 ones?H
0/14 letters found
Clue 2
Word problems
The thief left a code on a treasure chest. Count the tens and ones blocks to unlock it.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Awitnesssawthevillainwas .
U
28
21
38
21
20
38
40
6
10
A
N
D
6
O
W
A
V
38
There were 37 kelp cookies. 9 were used up. How many kelp cookies are left?U
There were 25 starfish toys. 5 were used up. How many starfish toys are left?L
There were 19 shiny pearls. 9 were used up. How many shiny pearls are left?H
The royal dolphin found 2 starfish toys yesterday and 4 more today. How many starfish toys in all?T
The royal dolphin lined up 4 rows of 10 blue bubbles. How many blue bubbles in all?F
There were 46 pink seashells. 8 were used up. How many pink seashells are left?E
The royal dolphin found 2 starfish toys yesterday and 19 more today. How many starfish toys in all?S
0/7 letters found
Clue 3
Addition
Let us add all these shiny shells together. The total sum will give us another 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
53
48
30
T
53
48
67
30
66
91
48
81
49
86
77
66
81
55
44
T
53
67
43
77
40
51
91
30
49
27
30
30
98
20 + 33 =T
32 + 49 =R
9 + 18 =W
22 + 33 =O
20 + 10 =E
33 + 44 =K
57 + 29 =N
23 + 17 =L
41 + 25 =F
23 + 21 =M
52 + 39 =S
19 + 30 =A
40 + 58 =D
15 + 28 =C
32 + 16 =H
16 + 35 =Y
43 + 24 =I
0/17 letters found
Clue 4
Subtraction
The thief dropped some sea-glass. If we take away the broken pieces, we can read the next 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.
W
76
69
45
36
47
30
34
73
14
12
30
55
82
69
73
82
52
69
16
16
67
37
36
W
76
30
101 - 25 =W
35 - 5 =N
68 - 34 =D
57 - 21 =O
43 - 31 =I
85 - 12 =A
19 - 5 =P
35 - 19 =L
98 - 31 =C
113 - 31 =S
50 - 5 =F
100 - 31 =E
65 - 10 =K
86 - 34 =H
49 - 12 =R
69 - 22 =U
0/16 letters found
Clue 5
Missing addends — the last clue
We have some empty clam shells. Fill in the missing numbers to open them and find 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
4 + ___ = 10
1 + ___ = 3
9 + ___ = 17
10 + ___ = 21
1 + ___ = 13
7 + ___ = 12
5 + ___ = 8
1 + ___ = 5
10 + ___ = 17
2 + ___ = 3
9 + ___ = 18
Step 2 — cross out the sentence with each answer
1.The villain dives into the deep reef, then hides behind the pink coral.
2.The villain giggles behind a rock, then tosses sand into the air.
3.The villain splashes the shiny water, then hides behind the pink coral.
4.The villain giggles behind a rock, then snatches the shiny star pearl.
5.The villain swishes their glittery tail, then rides a big sea turtle.
6.The villain swishes their glittery tail, then tosses sand into the air.
7.The villain giggles behind a rock, then rides a big sea turtle.
8.The villain splashes the shiny water, then snatches the shiny star pearl.
9.The villain dives into the deep reef, then zips away into a dark cave.
10.The villain swishes their glittery tail, then snatches the shiny star pearl.
11.The villain dives into the deep reef, then tosses sand into the air.
12.The villain surprises a friendly fish, then hides behind the pink coral.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of the Coral Cove Pearl
Culprit: Finn (swims super fast · finds shiny coins · uses left hand to wave · pink sea-shell crown · scared of tickly seaweed)
- Clue 1 (Place value): "THE THIEF DOES NOT SING SLEEPY TUNES"What number has 6 tens and 6 ones? = 66 (T) · What number has 8 tens and 2 ones? = 82 (G) · What number has 3 tens and 3 ones? = 33 (S) · What number has 7 tens and 3 ones? = 73 (P) · What number has 5 tens and 6 ones? = 56 (F) · What number has 6 tens and 4 ones? = 64 (D) · What number has 3 tens and 6 ones? = 36 (E) · What number has 1 ten and 9 ones? = 19 (I) · What number has 3 tens and 8 ones? = 38 (U) · What number has 4 tens and 5 ones? = 45 (Y) · What number has 6 tens and 1 one? = 61 (L) · What number has 3 tens and 5 ones? = 35 (N) · What number has 5 tens and 1 one? = 51 (O) · What number has 6 tens and 7 ones? = 67 (H)
- Clue 2 (Word problems): "USES LEFT HAND TO WAVE"There were 37 kelp cookies. 9 were used up. How many kelp cookies are left? = 28 (U) · There were 25 starfish toys. 5 were used up. How many starfish toys are left? = 20 (L) · There were 19 shiny pearls. 9 were used up. How many shiny pearls are left? = 10 (H) · The royal dolphin found 2 starfish toys yesterday and 4 more today. How many starfish toys in all? = 6 (T) · The royal dolphin lined up 4 rows of 10 blue bubbles. How many blue bubbles in all? = 40 (F) · There were 46 pink seashells. 8 were used up. How many pink seashells are left? = 38 (E) · The royal dolphin found 2 starfish toys yesterday and 19 more today. How many starfish toys in all? = 21 (S)
- Clue 3 (Addition): "THE THIEF SHRANK FROM TICKLY SEAWEED"20 + 33 = 53 (T) · 32 + 49 = 81 (R) · 9 + 18 = 27 (W) · 22 + 33 = 55 (O) · 20 + 10 = 30 (E) · 33 + 44 = 77 (K) · 57 + 29 = 86 (N) · 23 + 17 = 40 (L) · 41 + 25 = 66 (F) · 23 + 21 = 44 (M) · 52 + 39 = 91 (S) · 19 + 30 = 49 (A) · 40 + 58 = 98 (D) · 15 + 28 = 43 (C) · 32 + 16 = 48 (H) · 16 + 35 = 51 (Y) · 43 + 24 = 67 (I)
- Clue 4 (Subtraction): "WE FOUND A PINK SEASHELL CROWN"101 - 25 = 76 (W) · 35 - 5 = 30 (N) · 68 - 34 = 34 (D) · 57 - 21 = 36 (O) · 43 - 31 = 12 (I) · 85 - 12 = 73 (A) · 19 - 5 = 14 (P) · 35 - 19 = 16 (L) · 98 - 31 = 67 (C) · 113 - 31 = 82 (S) · 50 - 5 = 45 (F) · 100 - 31 = 69 (E) · 65 - 10 = 55 (K) · 86 - 34 = 52 (H) · 49 - 12 = 37 (R) · 69 - 22 = 47 (U)
- Clue 5 (Missing addends): surviving statement (box 10) → Finn4 + ___ = 10 = 6 · 1 + ___ = 3 = 2 · 9 + ___ = 17 = 8 · 10 + ___ = 21 = 11 · 1 + ___ = 13 = 12 · 7 + ___ = 12 = 5 · 5 + ___ = 8 = 3 · 1 + ___ = 5 = 4 · 10 + ___ = 17 = 7 · 2 + ___ = 3 = 1 · 9 + ___ = 18 = 9
About this mystery
- Grade level
- Grade 2 math
- Math topics
- Place value, Word problems, Addition, Subtraction, Missing addends
- Reading level
- grades 1-2
- Theme
- The Mystery of the Coral Cove Pearl — set in Coral Cove
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects