🦕 Robots, Dinosaurs, MermaidsGrade 1Reading: grades 1-2Place valueAdditionSubtractionSkip countingMissing addends
The Cyber-Coral Island Mystery
Someone stole the Magic Power Gem from Cyber-Coral Island! The Techno-Thief left a trail of gears and sea shells. The Aqua-Bot Crew needs your help to solve the math puzzles and catch them!
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 | Main Power | Special Tool | Dominant Hand | Hair Style | Weakness |
|---|---|---|---|---|---|
| Pearl | Shoots water jets | Spits hot steam | Left-handed | Silver metal wires | Salty sea water |
| Aqua Ann | Stomps heavy feet | Throws rusty gears | Left-handed | Silver metal wires | Strong magnets |
| Gizmo | Stomps heavy feet | Glows in the dark | Right-handed | Silver metal wires | Salty sea water |
| Finley | Stomps heavy feet | Launches fish nets | Right-handed | Pink coral crown | Strong magnets |
| Sprocket | Swims super fast | Zaps laser beams | Right-handed | Pink coral crown | Salty sea water |
| Robo Roberta | Roars like a Rex | Zaps laser beams | Left-handed | Silver metal wires | Salty sea water |
| Dino | Swims super fast | Glows in the dark | Left-handed | Pink coral crown | Bright flashlights |
| Salty Sally | Shoots water jets | Spits hot steam | Right-handed | Silver metal wires | Bright flashlights |
| Shellie | Stomps heavy feet | Glows in the dark | Right-handed | Pink coral crown | Salty sea water |
| Cyber Cody | Swims super fast | Zaps laser beams | Left-handed | Green seaweed hair | Strong magnets |
| Bolt | Stomps heavy feet | Glows in the dark | Left-handed | Silver metal wires | Bright flashlights |
| Stego Steve | Shoots water jets | Zaps laser beams | Right-handed | Silver metal wires | Bright flashlights |
| Marina | Roars like a Rex | Spits hot steam | Left-handed | Pink coral crown | Salty sea water |
| Wave | Hacks computers | Glows in the dark | Right-handed | Green seaweed hair | Bright flashlights |
| Anchor | Shoots water jets | Launches fish nets | Left-handed | Silver metal wires | Bright flashlights |
| Coral | Roars like a Rex | Glows in the dark | Right-handed | Silver metal wires | Bright flashlights |
| Pixel | Hacks computers | Glows in the dark | Left-handed | Silver metal wires | Strong magnets |
| Gears | Roars like a Rex | Spits hot steam | Right-handed | Silver metal wires | Bright flashlights |
| Splash | Hacks computers | Throws rusty gears | Right-handed | Silver metal wires | Bright flashlights |
| Talon | Hacks computers | Launches fish nets | Left-handed | Silver metal wires | Bright flashlights |
| Tricera Todd | Stomps heavy feet | Zaps laser beams | Left-handed | Silver metal wires | Strong magnets |
Clue 1
Place value
We scan the villain's digital footprint. The screen shows tens and ones blocks.
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
36
29
59
24
99
59
58
99
59
76
22
99
T
36
T
36
29
44
99
13
44
11
76
T
36
38
85
59
62
44
76
What number has 3 tens and 6 ones?T
What number has 1 ten and 1 one?U
What number has 6 tens and 2 ones?A
What number has 5 tens and 9 ones?E
What number has 8 tens and 5 ones?G
What number has 3 tens and 8 ones?Y
What number has 4 tens and 4 ones?R
What number has 7 tens and 6 ones?S
What number has 5 tens and 8 ones?D
What number has 9 tens and 9 ones?O
What number has 1 ten and 3 ones?W
What number has 2 tens and 2 ones?N
What number has 2 tens and 9 ones?H
What number has 2 tens and 4 ones?F
0/14 letters found
Clue 2
Addition
We find two piles of shiny sea shells on the beach. Let's add them together to get 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
20
7
17
9
3
8
8
4
3
15
6
12
17
19
T
20
7
17
3
18
18
3
13
7
T
20
7
4
15
19
10 + 10 =T
14 + 5 =D
2 + 5 =H
10 + 5 =N
3 + 1 =A
8 + 4 =S
2 + 1 =I
9 + 4 =G
6 + 3 =V
5 + 1 =U
10 + 7 =E
12 + 6 =R
4 + 4 =L
0/13 letters found
Clue 3
Subtraction
The robot guard lost some of its battery power cells. Let's subtract to see how many are left.
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
6
14
17
12
14
1
3
2
19
8
7
9
19
1
4
14
T
6
2
15
13
16
14
15
1
4
14
T
6
16
11 - 5 =T
17 - 3 =H
6 - 3 =D
13 - 1 =Y
12 - 3 =B
5 - 4 =I
19 - 3 =S
11 - 3 =O
15 - 2 =A
11 - 4 =M
17 - 2 =L
9 - 5 =G
20 - 1 =R
3 - 1 =F
18 - 1 =E
0/15 letters found
Clue 4
Skip counting
We see dinosaur tracks in the mud. Let's count them by twos to follow the 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.
W
120
42
25
9
14
100
26
30
110
80
140
42
12
65
42
50
70
80
W
120
110
12
42
30
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140W
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, ___, 150, 160V
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130I
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80A
Skip-count by 3s. Fill the blank: 3, 6, ___, 12, 15O
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18U
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, ___, 33, 36S
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75M
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, ___, 55, 60T
Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35F
Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48E
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, ___, 14, 16R
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120N
Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100L
Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30D
0/15 letters found
Clue 5
Missing addends — the last clue
We need ten fuel cans to start our submarine. We have six. Let's find how many more we need.
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
3 + ___ = 12
5 + ___ = 15
2 + ___ = 4
4 + ___ = 10
5 + ___ = 10
8 + ___ = 12
7 + ___ = 10
7 + ___ = 15
3 + ___ = 10
1 + ___ = 2
10 + ___ = 22
Step 2 — cross out the sentence with each answer
1.The villain roars like a giant T-Rex, then zaps a yellow laser beam.
2.The villain roars like a giant T-Rex, then glows bright in the dark.
3.The villain shoots a big water jet, then throws rusty metal gears.
4.The villain swims through the deep ocean, then launches a giant fish net.
5.The villain stomps with heavy metal feet, then glows bright in the dark.
6.The villain stomps with heavy metal feet, then launches a giant fish net.
7.The villain hacks the main computer, then throws rusty metal gears.
8.The villain stomps with heavy metal feet, then throws rusty metal gears.
9.The villain shoots a big water jet, then zaps a yellow laser beam.
10.The villain shoots a big water jet, then spits out hot cloud steam.
11.The villain roars like a giant T-Rex, then spits out hot cloud steam.
12.The villain stomps with heavy metal feet, then spits out hot cloud steam.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Cyber-Coral Island Mystery
Culprit: Gears (Roars like a Rex · Spits hot steam · Right-handed · Silver metal wires · Bright flashlights)
- Clue 1 (Place value): "THE FOE DOES NOT THROW RUSTY GEARS"What number has 3 tens and 6 ones? = 36 (T) · What number has 1 ten and 1 one? = 11 (U) · What number has 6 tens and 2 ones? = 62 (A) · What number has 5 tens and 9 ones? = 59 (E) · What number has 8 tens and 5 ones? = 85 (G) · What number has 3 tens and 8 ones? = 38 (Y) · What number has 4 tens and 4 ones? = 44 (R) · What number has 7 tens and 6 ones? = 76 (S) · What number has 5 tens and 8 ones? = 58 (D) · What number has 9 tens and 9 ones? = 99 (O) · What number has 1 ten and 3 ones? = 13 (W) · What number has 2 tens and 2 ones? = 22 (N) · What number has 2 tens and 9 ones? = 29 (H) · What number has 2 tens and 4 ones? = 24 (F)
- Clue 2 (Addition): "THE VILLAIN USED THEIR RIGHT HAND"10 + 10 = 20 (T) · 14 + 5 = 19 (D) · 2 + 5 = 7 (H) · 10 + 5 = 15 (N) · 3 + 1 = 4 (A) · 8 + 4 = 12 (S) · 2 + 1 = 3 (I) · 9 + 4 = 13 (G) · 6 + 3 = 9 (V) · 5 + 1 = 6 (U) · 10 + 7 = 17 (E) · 12 + 6 = 18 (R) · 4 + 4 = 8 (L)
- Clue 3 (Subtraction): "THEY HID FROM BRIGHT FLASHLIGHTS"11 - 5 = 6 (T) · 17 - 3 = 14 (H) · 6 - 3 = 3 (D) · 13 - 1 = 12 (Y) · 12 - 3 = 9 (B) · 5 - 4 = 1 (I) · 19 - 3 = 16 (S) · 11 - 3 = 8 (O) · 15 - 2 = 13 (A) · 11 - 4 = 7 (M) · 17 - 2 = 15 (L) · 9 - 5 = 4 (G) · 20 - 1 = 19 (R) · 3 - 1 = 2 (F) · 18 - 1 = 17 (E)
- Clue 4 (Skip counting): "WE FOUND SILVER METAL WIRES"Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, ___, 130, 140 = 120 (W) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, ___, 150, 160 = 140 (V) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, ___, 120, 130 = 110 (I) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, ___, 75, 80 = 70 (A) · Skip-count by 3s. Fill the blank: 3, 6, ___, 12, 15 = 9 (O) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, ___, 16, 18 = 14 (U) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, ___, 33, 36 = 30 (S) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, ___, 70, 75 = 65 (M) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, 25, 30, 35, 40, 45, ___, 55, 60 = 50 (T) · Skip-count by 5s. Fill the blank: 5, 10, 15, 20, ___, 30, 35 = 25 (F) · Skip-count by 3s. Fill the blank: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, ___, 45, 48 = 42 (E) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, ___, 14, 16 = 12 (R) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, 80, 90, ___, 110, 120 = 100 (N) · Skip-count by 10s. Fill the blank: 10, 20, 30, 40, 50, 60, 70, ___, 90, 100 = 80 (L) · Skip-count by 2s. Fill the blank: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, ___, 28, 30 = 26 (D)
- Clue 5 (Missing addends): surviving statement (box 11) → Gears3 + ___ = 12 = 9 · 5 + ___ = 15 = 10 · 2 + ___ = 4 = 2 · 4 + ___ = 10 = 6 · 5 + ___ = 10 = 5 · 8 + ___ = 12 = 4 · 7 + ___ = 10 = 3 · 7 + ___ = 15 = 8 · 3 + ___ = 10 = 7 · 1 + ___ = 2 = 1 · 10 + ___ = 22 = 12
About this mystery
- Grade level
- Grade 1 math
- Math topics
- Place value, Addition, Subtraction, Skip counting, Missing addends
- Reading level
- grades 1-2
- Theme
- The Cyber-Coral Island Mystery — set in Cyber-Coral Island
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects