🌊 Mermaids, UnicornsGrade 1Reading: grades 1-2AdditionSubtractionSkip countingPlace valueMissing addends
The Grotto Pearl Mystery
Someone took the royal rainbow pearl from the underwater palace! The sea creatures and magical unicorns need your help to find the thief.
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 | Magic Spell | Sparkle Trail | Accessory | Hair Color | Secret Weakness |
|---|---|---|---|---|---|
| Caspian | bubble blast | sea sparkle | sea glass ring | coral pink hair | floating seaweed |
| Kai | coral shield | glitter trail | pearl bracelet | sunshine gold hair | noisy clams |
| Sandy | star shine | crystal horn | sea glass ring | sunshine gold hair | noisy clams |
| Starla | star shine | sea sparkle | sea glass ring | ocean blue hair | shiny mirrors |
| Opal | star shine | pearl glow | sea glass ring | coral pink hair | floating seaweed |
| Marina | coral shield | sea sparkle | pearl bracelet | sunshine gold hair | shiny mirrors |
| Astra | prism beam | rainbow leap | sea glass ring | sunshine gold hair | floating seaweed |
| Pearl | bubble blast | pearl glow | pearl bracelet | ocean blue hair | floating seaweed |
| Delphin | star shine | glitter trail | sea glass ring | sunshine gold hair | floating seaweed |
| Sunny | coral shield | glitter trail | pearl bracelet | ocean blue hair | floating seaweed |
| Wave | coral shield | pearl glow | pearl bracelet | coral pink hair | floating seaweed |
| Coral | tide wave | rainbow leap | sea glass ring | coral pink hair | floating seaweed |
| Triton | star shine | pearl glow | pearl bracelet | ocean blue hair | noisy clams |
| Drift | prism beam | sea sparkle | sea glass ring | coral pink hair | shiny mirrors |
| Bubbles | coral shield | glitter trail | pearl bracelet | ocean blue hair | noisy clams |
| Coralie | tide wave | glitter trail | sea glass ring | coral pink hair | shiny mirrors |
| Splash | bubble blast | glitter trail | sea glass ring | coral pink hair | shiny mirrors |
| Orion | tide wave | crystal horn | pearl bracelet | sunshine gold hair | floating seaweed |
| Shelly | bubble blast | pearl glow | sea glass ring | sunshine gold hair | floating seaweed |
| Tide | prism beam | sea sparkle | sea glass ring | coral pink hair | floating seaweed |
| Finny | tide wave | crystal horn | sea glass ring | coral pink hair | floating seaweed |
Clue 1
Addition
Captain Pearl added up all the shiny shells found near the reef to reveal the first code.
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
18
3
17
16
12
10
10
20
12
8
11
6
17
4
8
6
T
18
3
20
16
17
20
19
15
7
4
T
18
20
10
3
6
15
8
7 + 11 =T
2 + 1 =H
3 + 1 =S
12 + 8 =A
6 + 11 =E
2 + 4 =O
5 + 3 =N
4 + 11 =R
9 + 7 =V
4 + 6 =L
3 + 8 =D
12 + 7 =C
6 + 6 =I
4 + 3 =Y
0/14 letters found
Clue 2
Subtraction
Finny the seahorse swam past and subtracted the dull rocks from the pile.
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
5
7
4
10
8
2
2
2
9
W
5
9
2
8
9
11
13
9
2
2
6
7
10
11
17
10
4
15
8
15
9
10
16
9 - 4 =W
18 - 9 =A
20 - 4 =D
15 - 8 =I
8 - 6 =S
20 - 9 =G
11 - 3 =E
10 - 6 =T
9 - 3 =R
18 - 8 =N
19 - 2 =O
19 - 4 =H
14 - 1 =L
0/13 letters found
Clue 3
Skip counting
Marina skip counted the magic star gems along the sandy path.
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
8
110
36
20
120
36
35
65
6
100
T
8
T
8
90
15
65
130
36
140
16
40
21
130
100
35
T
8
90
120
6
20
36
35
50
36
36
140
Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12T
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27F
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21C
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110I
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, ___, 150, 160D
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130H
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75K
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, ___, 22, 24S
Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10G
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42E
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140N
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, ___, 55, 60W
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20B
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45A
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, ___, 45, 50Y
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120O
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150L
0/17 letters found
Clue 4
Place value
The glowing grotto board shows the tens and ones place for this 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.
S
40
87
96
46
33
26
S
40
64
27
67
64
96
46
21
98
92
33
83
25
46
92
96
89
76
96
76
27
64
38
33
26
What number has 4 tens and 0 ones?S
What number has 3 tens and 8 ones?U
What number has 9 tens and 6 ones?R
What number has 9 tens and 8 ones?P
What number has 2 tens and 5 ones?H
What number has 3 tens and 3 ones?N
What number has 6 tens and 7 ones?C
What number has 8 tens and 9 ones?W
What number has 7 tens and 6 ones?E
What number has 6 tens and 4 ones?O
What number has 2 tens and 1 one?L
What number has 2 tens and 7 ones?F
What number has 4 tens and 6 ones?A
What number has 8 tens and 7 ones?T
What number has 9 tens and 2 ones?I
What number has 8 tens and 3 ones?K
What number has 2 tens and 6 ones?D
0/17 letters found
Clue 5
Missing addends — the last clue
Splash needs to figure out the missing number of pearls to unlock the final message.
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
10 + ___ = 12
4 + ___ = 13
6 + ___ = 9
5 + ___ = 11
2 + ___ = 6
2 + ___ = 7
1 + ___ = 11
9 + ___ = 10
5 + ___ = 12
1 + ___ = 13
8 + ___ = 19
Step 2 — cross out the sentence with each answer
1.The villain shot a bubble blast, then used a crystal horn.
2.The villain shot a bubble blast, then made a sea sparkle.
3.The villain made a tide wave, then made a rainbow leap.
4.The villain shot a bubble blast, then made a rainbow leap.
5.The villain used a coral shield, then lit a pearl glow.
6.The villain used a coral shield, then left a glitter trail.
7.The villain made a star shine, then used a crystal horn.
8.The villain cast a prism beam, then made a sea sparkle.
9.The villain made a star shine, then lit a pearl glow.
10.The villain cast a prism beam, then made a rainbow leap.
11.The villain shot a bubble blast, then left a glitter trail.
12.The villain made a tide wave, then made a sea sparkle.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Grotto Pearl Mystery
Culprit: Tide (prism beam · sea sparkle · sea glass ring · coral pink hair · floating seaweed)
- Clue 1 (Addition): "THE VILLAIN DOES NOT HAVE A CRYSTAL HORN"7 + 11 = 18 (T) · 2 + 1 = 3 (H) · 3 + 1 = 4 (S) · 12 + 8 = 20 (A) · 6 + 11 = 17 (E) · 2 + 4 = 6 (O) · 5 + 3 = 8 (N) · 4 + 11 = 15 (R) · 9 + 7 = 16 (V) · 4 + 6 = 10 (L) · 3 + 8 = 11 (D) · 12 + 7 = 19 (C) · 6 + 6 = 12 (I) · 4 + 3 = 7 (Y)
- Clue 2 (Subtraction): "WITNESS SAW A SEA GLASS RING ON THE HAND"9 - 4 = 5 (W) · 18 - 9 = 9 (A) · 20 - 4 = 16 (D) · 15 - 8 = 7 (I) · 8 - 6 = 2 (S) · 20 - 9 = 11 (G) · 11 - 3 = 8 (E) · 10 - 6 = 4 (T) · 9 - 3 = 6 (R) · 18 - 8 = 10 (N) · 19 - 2 = 17 (O) · 19 - 4 = 15 (H) · 14 - 1 = 13 (L)
- Clue 3 (Skip counting): "THE SNEAK GOT TICKLED BY FLOATING SEAWEED"Skip-count by 2s. Fill the blank: 2, 4, 6, ___, 10, 12 = 8 (T) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, ___, 24, 27 = 21 (F) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, ___, 18, 21 = 15 (C) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, ___, 100, 110 = 90 (I) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, ___, 150, 160 = 140 (D) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130 = 110 (H) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75 = 65 (K) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, ___, 22, 24 = 20 (S) · Skip-count by 2s. Fill the blank: 2, 4, ___, 8, 10 = 6 (G) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, ___, 39, 42 = 36 (E) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140 = 120 (N) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, ___, 55, 60 = 50 (W) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, ___, 18, 20 = 16 (B) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, ___, 40, 45 = 35 (A) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, ___, 45, 50 = 40 (Y) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120 = 100 (O) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, ___, 140, 150 = 130 (L)
- Clue 4 (Place value): "STRANDS OF CORAL PINK HAIR WERE FOUND"What number has 4 tens and 0 ones? = 40 (S) · What number has 3 tens and 8 ones? = 38 (U) · What number has 9 tens and 6 ones? = 96 (R) · What number has 9 tens and 8 ones? = 98 (P) · What number has 2 tens and 5 ones? = 25 (H) · What number has 3 tens and 3 ones? = 33 (N) · What number has 6 tens and 7 ones? = 67 (C) · What number has 8 tens and 9 ones? = 89 (W) · What number has 7 tens and 6 ones? = 76 (E) · What number has 6 tens and 4 ones? = 64 (O) · What number has 2 tens and 1 one? = 21 (L) · What number has 2 tens and 7 ones? = 27 (F) · What number has 4 tens and 6 ones? = 46 (A) · What number has 8 tens and 7 ones? = 87 (T) · What number has 9 tens and 2 ones? = 92 (I) · What number has 8 tens and 3 ones? = 83 (K) · What number has 2 tens and 6 ones? = 26 (D)
- Clue 5 (Missing addends): surviving statement (box 8) → Tide10 + ___ = 12 = 2 · 4 + ___ = 13 = 9 · 6 + ___ = 9 = 3 · 5 + ___ = 11 = 6 · 2 + ___ = 6 = 4 · 2 + ___ = 7 = 5 · 1 + ___ = 11 = 10 · 9 + ___ = 10 = 1 · 5 + ___ = 12 = 7 · 1 + ___ = 13 = 12 · 8 + ___ = 19 = 11
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Addition, Subtraction, Skip counting, Place value, Missing addends
- Reading level
- grades 1-2
- Theme
- The Grotto Pearl Mystery — set in Rainbow Grotto
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects