🌊 MermaidsGrade 1Reading: grades 1-2AdditionPlace valueWord problemsRoundingMissing addends
The Mystery of the Missing Rainbow Pearl
A sneaky thief took the Great Rainbow Pearl from Coral Cove Reef! Detective Splash needs your help to solve the math clues and find out who took it before the big reef party.
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 Power | Swimming Style | Hair Color | Weakness |
|---|---|---|---|---|---|
| Finley | Tail Whip | Singing Waves | Right Fin Waving | Coral Pink | Scared Of Sharks |
| Splash | Tide Call | Glow Fins | Right Fin Waving | Ocean Blue | Tickled By Crab |
| Nixie | Tide Call | Deep Diving | Left Fin Waving | Ocean Blue | Tickled By Crab |
| Triton | Pearl Zap | Star Power | Right Fin Waving | Seaweed Green | Tickled By Crab |
| Sandy | Tail Whip | Deep Diving | Left Fin Waving | Ocean Blue | Scared Of Sharks |
| Pearl | Bubble Shield | Fast Swimming | Right Fin Waving | Coral Pink | Bright Flashlight |
| Atlantis | Coral Armor | Deep Diving | Left Fin Waving | Ocean Blue | Tickled By Crab |
| Bubbles | Pearl Zap | Singing Waves | Right Fin Waving | Coral Pink | Tickled By Crab |
| Kelp | Pearl Zap | Fast Swimming | Right Fin Waving | Ocean Blue | Bright Flashlight |
| Current | Tide Call | Fast Swimming | Left Fin Waving | Seaweed Green | Bright Flashlight |
| Reef | Tide Call | Star Power | Right Fin Waving | Seaweed Green | Bright Flashlight |
| Wave | Bubble Shield | Glow Fins | Right Fin Waving | Ocean Blue | Tickled By Crab |
| Nautica | Bubble Shield | Singing Waves | Left Fin Waving | Seaweed Green | Scared Of Sharks |
| Ray | Bubble Shield | Star Power | Left Fin Waving | Ocean Blue | Scared Of Sharks |
| Shelly | Coral Armor | Deep Diving | Right Fin Waving | Coral Pink | Bright Flashlight |
| Misty | Coral Armor | Deep Diving | Right Fin Waving | Ocean Blue | Tickled By Crab |
| Cascade | Pearl Zap | Deep Diving | Right Fin Waving | Ocean Blue | Tickled By Crab |
| Marina | Tail Whip | Deep Diving | Right Fin Waving | Seaweed Green | Tickled By Crab |
| Delphine | Tide Call | Star Power | Right Fin Waving | Ocean Blue | Tickled By Crab |
| Ariel | Coral Armor | Fast Swimming | Left Fin Waving | Ocean Blue | Tickled By Crab |
| Kai | Bubble Shield | Fast Swimming | Right Fin Waving | Ocean Blue | Tickled By Crab |
Clue 1
Addition
We need to count all the shells found near the shell throne to find the first 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
3
20
11
19
5
9
9
7
5
8
18
13
11
10
8
13
T
3
20
7
19
11
18
11
11
17
18
5
19
5
8
6
2 + 1 =T
13 + 5 =D
6 + 13 =V
7 + 10 =P
4 + 4 =N
7 + 3 =S
2 + 7 =L
3 + 3 =G
3 + 2 =I
5 + 2 =A
9 + 4 =O
11 + 9 =H
3 + 8 =E
0/13 letters found
Clue 2
Place value
Look at the tens and ones on the glowing reef board to unlock the next secret.
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
60
31
52
59
18
T
60
29
52
12
12
12
70
59
70
39
18
95
31
T
60
26
18
29
59
70
87
18
29
95
What number has 6 tens and 0 ones?T
What number has 1 ten and 2 ones?S
What number has 3 tens and 1 one?H
What number has 5 tens and 2 ones?E
What number has 7 tens and 0 ones?A
What number has 5 tens and 9 ones?W
What number has 9 tens and 5 ones?G
What number has 1 ten and 8 ones?I
What number has 2 tens and 6 ones?F
What number has 2 tens and 9 ones?N
What number has 8 tens and 7 ones?V
What number has 3 tens and 9 ones?R
0/12 letters found
Clue 3
Word problems
Solve this sea problem to hear what the tiny hermit crab saw.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Someonescaredthevillainoffwith .
T
23
11
15
38
16
17
33
B
Y
15
R
A
B
There were 32 pearls. 9 were used up. How many pearls are left?T
Mermaid Coral found 8 sea glass pieces yesterday and 3 more today. How many sea glass pieces in all?I
Mermaid Coral lined up 5 rows of 3 pearls. How many pearls in all?C
Mermaid Coral found 15 glow stones yesterday and 23 more today. How many glow stones in all?K
Mermaid Coral found 6 sea glass pieces yesterday and 10 more today. How many sea glass pieces in all?L
Mermaid Coral lined up 11 rows of 3 glow stones. How many glow stones in all?D
There were 20 shiny shells. 3 were used up. How many shiny shells are left?E
0/7 letters found
Clue 4
Rounding
The sonar screen rounds the distance to the nearest ten to spot the villain.
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
80
300
500
700
900
A
80
300
800
30
600
900
50
A
80
60
70
400
A
80
200
90
500
600
300
20
Round 77 to the nearest tenA
Round 604 to the nearest hundredU
Round 889 to the nearest hundredE
Round 727 to the nearest hundredC
Round 19 to the nearest tenD
Round 93 to the nearest tenF
Round 398 to the nearest hundredW
Round 820 to the nearest hundredB
Round 241 to the nearest hundredS
Round 48 to the nearest tenH
Round 71 to the nearest tenR
Round 328 to the nearest hundredN
Round 30 to the nearest tenL
Round 57 to the nearest tenI
Round 516 to the nearest hundredO
0/15 letters found
Clue 5
Missing addends — the last clue
Find the missing number of bubbles to decode 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
4 + ___ = 8
8 + ___ = 15
3 + ___ = 6
1 + ___ = 7
5 + ___ = 7
6 + ___ = 16
4 + ___ = 13
8 + ___ = 9
1 + ___ = 9
1 + ___ = 13
2 + ___ = 13
Step 2 — cross out the sentence with each answer
1.The villain shot a pearl zap, then started singing waves.
2.The villain put on coral armor, then used star power.
3.The villain made a bubble shield, then flashed glow fins.
4.The villain used a tide call, then used star power.
5.The villain made a bubble shield, then did fast swimming.
6.The villain put on coral armor, then started singing waves.
7.The villain used a tide call, then flashed glow fins.
8.The villain used a tail whip, then did fast swimming.
9.The villain put on coral armor, then went deep diving.
10.The villain used a tide call, then started singing waves.
11.The villain used a tail whip, then flashed glow fins.
12.The villain used a tide call, then went deep diving.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of the Missing Rainbow Pearl
Culprit: Kai (Bubble Shield · Fast Swimming · Right Fin Waving · Ocean Blue · Tickled By Crab)
- Clue 1 (Addition): "THE VILLAIN DOES NOT HAVE DEEP DIVING"2 + 1 = 3 (T) · 13 + 5 = 18 (D) · 6 + 13 = 19 (V) · 7 + 10 = 17 (P) · 4 + 4 = 8 (N) · 7 + 3 = 10 (S) · 2 + 7 = 9 (L) · 3 + 3 = 6 (G) · 3 + 2 = 5 (I) · 5 + 2 = 7 (A) · 9 + 4 = 13 (O) · 11 + 9 = 20 (H) · 3 + 8 = 11 (E)
- Clue 2 (Place value): "THE WITNESS SAW A RIGHT FIN WAVING"What number has 6 tens and 0 ones? = 60 (T) · What number has 1 ten and 2 ones? = 12 (S) · What number has 3 tens and 1 one? = 31 (H) · What number has 5 tens and 2 ones? = 52 (E) · What number has 7 tens and 0 ones? = 70 (A) · What number has 5 tens and 9 ones? = 59 (W) · What number has 9 tens and 5 ones? = 95 (G) · What number has 1 ten and 8 ones? = 18 (I) · What number has 2 tens and 6 ones? = 26 (F) · What number has 2 tens and 9 ones? = 29 (N) · What number has 8 tens and 7 ones? = 87 (V) · What number has 3 tens and 9 ones? = 39 (R)
- Clue 3 (Word problems): "TICKLED BY CRAB"There were 32 pearls. 9 were used up. How many pearls are left? = 23 (T) · Mermaid Coral found 8 sea glass pieces yesterday and 3 more today. How many sea glass pieces in all? = 11 (I) · Mermaid Coral lined up 5 rows of 3 pearls. How many pearls in all? = 15 (C) · Mermaid Coral found 15 glow stones yesterday and 23 more today. How many glow stones in all? = 38 (K) · Mermaid Coral found 6 sea glass pieces yesterday and 10 more today. How many sea glass pieces in all? = 16 (L) · Mermaid Coral lined up 11 rows of 3 glow stones. How many glow stones in all? = 33 (D) · There were 20 shiny shells. 3 were used up. How many shiny shells are left? = 17 (E)
- Clue 4 (Rounding): "AN OCEAN BLUE HAIR WAS FOUND"Round 77 to the nearest ten = 80 (A) · Round 604 to the nearest hundred = 600 (U) · Round 889 to the nearest hundred = 900 (E) · Round 727 to the nearest hundred = 700 (C) · Round 19 to the nearest ten = 20 (D) · Round 93 to the nearest ten = 90 (F) · Round 398 to the nearest hundred = 400 (W) · Round 820 to the nearest hundred = 800 (B) · Round 241 to the nearest hundred = 200 (S) · Round 48 to the nearest ten = 50 (H) · Round 71 to the nearest ten = 70 (R) · Round 328 to the nearest hundred = 300 (N) · Round 30 to the nearest ten = 30 (L) · Round 57 to the nearest ten = 60 (I) · Round 516 to the nearest hundred = 500 (O)
- Clue 5 (Missing addends): surviving statement (box 5) → Kai4 + ___ = 8 = 4 · 8 + ___ = 15 = 7 · 3 + ___ = 6 = 3 · 1 + ___ = 7 = 6 · 5 + ___ = 7 = 2 · 6 + ___ = 16 = 10 · 4 + ___ = 13 = 9 · 8 + ___ = 9 = 1 · 1 + ___ = 9 = 8 · 1 + ___ = 13 = 12 · 2 + ___ = 13 = 11
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Addition, Place value, Word problems, Rounding, Missing addends
- Reading level
- grades 1-2
- Theme
- The Mystery of the Missing Rainbow Pearl — set in Coral Cove Reef
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects