🌊 MermaidsGrade 1Reading: grades 1-2AdditionMultiplicationSubtractionSkip countingDivision
The Mystery of the Missing Royal Pearl
Someone took the royal crown pearl from Coral Cove Palace! Use your math skills to help the Mermaid Patrol find 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 | Special Move | Mermaid Gear | Bracelet Arm | Tail Fin Color | Secret Weakness |
|---|---|---|---|---|---|
| Kai | tide whip | star fin | wears left bracelet | blue tail fins | tickled by seaweed |
| Nerida | song call | glow tail | wears right bracelet | blue tail fins | tickled by seaweed |
| Maris | bubble shield | shell armor | wears right bracelet | gold tail fins | tickled by seaweed |
| Sandy | bubble shield | glow tail | wears right bracelet | pink tail fins | tickled by seaweed |
| Marina | wave dash | glow tail | wears right bracelet | blue tail fins | tickled by seaweed |
| Reef | song call | glow tail | wears left bracelet | pink tail fins | scared of crabs |
| Pearl | wave dash | star fin | wears right bracelet | gold tail fins | tickled by seaweed |
| Coralline | tide whip | sea glass lens | wears left bracelet | pink tail fins | scared of crabs |
| Splash | bubble shield | star fin | wears right bracelet | gold tail fins | tickled by seaweed |
| Coral | pearl blast | glow tail | wears right bracelet | blue tail fins | tickled by seaweed |
| Breeze | pearl blast | shell armor | wears right bracelet | blue tail fins | scared of crabs |
| Aqua | song call | glow tail | wears right bracelet | gold tail fins | tickled by seaweed |
| Delphine | tide whip | star fin | wears right bracelet | gold tail fins | startled by guppies |
| Nixie | pearl blast | shell armor | wears right bracelet | gold tail fins | tickled by seaweed |
| Tide | song call | star fin | wears right bracelet | pink tail fins | tickled by seaweed |
| Delta | pearl blast | shell armor | wears left bracelet | blue tail fins | startled by guppies |
| Harbor | bubble shield | sea glass lens | wears right bracelet | blue tail fins | tickled by seaweed |
| Ocean | wave dash | shell armor | wears right bracelet | gold tail fins | startled by guppies |
| Waverly | wave dash | shell armor | wears left bracelet | blue tail fins | scared of crabs |
| Ray | tide whip | star fin | wears left bracelet | gold tail fins | tickled by seaweed |
| Ariel | song call | kelp cape | wears right bracelet | blue tail fins | tickled by seaweed |
Clue 1
Addition
Count the shining pearls we found in the sand to decode the first secret message.
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
13
2
14
8
4
20
20
12
4
19
17
3
14
7
19
3
T
13
9
14
12
6
12
15
14
20
16
10
12
16
14
9 + 4 =T
2 + 5 =S
1 + 2 =O
5 + 7 =A
9 + 6 =K
7 + 7 =E
6 + 4 =C
1 + 3 =I
4 + 4 =V
9 + 11 =L
1 + 1 =H
4 + 2 =R
5 + 4 =W
11 + 8 =N
11 + 5 =P
6 + 11 =D
0/16 letters found
Clue 2
Multiplication facts (1-12)
The sea turtles swim in equal groups across the reef to reveal the next hint.
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
30
84
15
32
28
32
16
15
18
T
30
33
15
121
42
32
121
8
42
121
18
15
77
15
T
30
14
6
T
30
84
15
42
24
54
84
T
30
6 × 5 =T
3 × 11 =W
6 × 3 =C
7 × 12 =H
11 × 7 =L
3 × 2 =N
2 × 7 =O
3 × 8 =I
4 × 7 =U
5 × 3 =E
4 × 2 =B
9 × 6 =G
11 × 11 =A
4 × 8 =S
6 × 7 =R
2 × 8 =P
0/16 letters found
Clue 3
Subtraction
Some glow shells floated away from our basket. Subtract them to unlock 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
16
6
13
18
12
15
15
2
12
9
4
2
14
T
16
12
8
3
15
13
1
17
19
14
13
2
4
13
13
1
20 - 4 =T
12 - 9 =K
20 - 1 =Y
17 - 3 =S
5 - 3 =A
16 - 3 =E
10 - 6 =W
20 - 2 =V
10 - 9 =D
16 - 4 =I
17 - 9 =C
11 - 2 =N
18 - 3 =L
14 - 8 =H
20 - 3 =B
0/15 letters found
Clue 4
Skip counting
Follow the trail of shiny starfish by skip counting along the sea floor.
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
65
130
40
25
9
40
20
40
130
30
16
14
24
10
40
T
65
30
6
24
28
6
20
25
24
40
28
T
65
14
40
130
6
20
16
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75T
Skip-count by 5s. Fill the blank: 5, 10, 15, ___, 25, 30N
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20D
Skip-count by 3s. Fill the blank: 3, 6, ___, 12, 15C
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150H
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, ___, 45, 50E
Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10I
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14U
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, ___, 30, 32F
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35S
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18B
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, ___, 35, 40A
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, ___, 27, 30L
0/13 letters found
Clue 5
Division facts (1-12) — the last clue
Share the sea glass gems equally among the clam shells to uncover the final 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
144 ÷ 12 = ?
45 ÷ 5 = ?
2 ÷ 1 = ?
20 ÷ 5 = ?
11 ÷ 11 = ?
48 ÷ 6 = ?
54 ÷ 9 = ?
6 ÷ 2 = ?
35 ÷ 5 = ?
30 ÷ 6 = ?
60 ÷ 6 = ?
Step 2 — cross out the sentence with each answer
1.The villain raised a bubble shield, then shined a shell armor.
2.The villain used a wave dash, then flashed a glow tail.
3.The villain raised a bubble shield, then flashed a glow tail.
4.The villain raised a bubble shield, then waved a star fin.
5.The villain shot a pearl blast, then swung a kelp cape.
6.The villain sang a song call, then looked through a sea glass lens.
7.The villain used a wave dash, then waved a star fin.
8.The villain cracked a tide whip, then swung a kelp cape.
9.The villain shot a pearl blast, then flashed a glow tail.
10.The villain used a wave dash, then shined a shell armor.
11.The villain raised a bubble shield, then looked through a sea glass lens.
12.The villain sang a song call, then flashed a glow tail.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of the Missing Royal Pearl
Culprit: Harbor (bubble shield · sea glass lens · wears right bracelet · blue tail fins · tickled by seaweed)
- Clue 1 (Addition): "THE VILLAIN DOES NOT WEAR A KELP CAPE"9 + 4 = 13 (T) · 2 + 5 = 7 (S) · 1 + 2 = 3 (O) · 5 + 7 = 12 (A) · 9 + 6 = 15 (K) · 7 + 7 = 14 (E) · 6 + 4 = 10 (C) · 1 + 3 = 4 (I) · 4 + 4 = 8 (V) · 9 + 11 = 20 (L) · 1 + 1 = 2 (H) · 4 + 2 = 6 (R) · 5 + 4 = 9 (W) · 11 + 8 = 19 (N) · 11 + 5 = 16 (P) · 6 + 11 = 17 (D)
- Clue 2 (Multiplication facts (1-12)): "THE SUSPECT WEARS A BRACELET ON THE RIGHT"6 × 5 = 30 (T) · 3 × 11 = 33 (W) · 6 × 3 = 18 (C) · 7 × 12 = 84 (H) · 11 × 7 = 77 (L) · 3 × 2 = 6 (N) · 2 × 7 = 14 (O) · 3 × 8 = 24 (I) · 4 × 7 = 28 (U) · 5 × 3 = 15 (E) · 4 × 2 = 8 (B) · 9 × 6 = 54 (G) · 11 × 11 = 121 (A) · 4 × 8 = 32 (S) · 6 × 7 = 42 (R) · 2 × 8 = 16 (P)
- Clue 3 (Subtraction): "THE VILLAIN WAS TICKLED BY SEAWEED"20 - 4 = 16 (T) · 12 - 9 = 3 (K) · 20 - 1 = 19 (Y) · 17 - 3 = 14 (S) · 5 - 3 = 2 (A) · 16 - 3 = 13 (E) · 10 - 6 = 4 (W) · 20 - 2 = 18 (V) · 10 - 9 = 1 (D) · 16 - 4 = 12 (I) · 17 - 9 = 8 (C) · 11 - 2 = 9 (N) · 18 - 3 = 15 (L) · 14 - 8 = 6 (H) · 20 - 3 = 17 (B)
- Clue 4 (Skip counting): "THE SCENE HAD BLUE TAIL FINS LEFT BEHIND"Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75 = 65 (T) · Skip-count by 5s. Fill the blank: 5, 10, 15, ___, 25, 30 = 20 (N) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20 = 16 (D) · Skip-count by 3s. Fill the blank: 3, 6, ___, 12, 15 = 9 (C) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150 = 130 (H) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, ___, 45, 50 = 40 (E) · Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10 = 6 (I) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, ___, 12, 14 = 10 (U) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, ___, 30, 32 = 28 (F) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35 = 25 (S) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18 = 14 (B) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, ___, 35, 40 = 30 (A) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, ___, 27, 30 = 24 (L)
- Clue 5 (Division facts (1-12)): surviving statement (box 11) → Harbor144 ÷ 12 = 12 · 45 ÷ 5 = 9 · 2 ÷ 1 = 2 · 20 ÷ 5 = 4 · 11 ÷ 11 = 1 · 48 ÷ 6 = 8 · 54 ÷ 9 = 6 · 6 ÷ 2 = 3 · 35 ÷ 5 = 7 · 30 ÷ 6 = 5 · 60 ÷ 6 = 10
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Addition, Multiplication, Subtraction, Skip counting, Division
- Reading level
- grades 1-2
- Theme
- The Mystery of the Missing Royal Pearl — set in Coral Cove Palace
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects