Grade 4Reading: grades 3-4RoundingAdditionSubtractionMultiplicationDivision
The Sapphire Island Map Mystery
Someone snuck into the camp tent and swiped the golden compass map! Detective, help us inspect the island clues to find out who did it.
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 | Jungle Gear | Island Tool | Stance | Bandana Color | Scent Dislike |
|---|---|---|---|---|---|
| Una Underwood | Climbing Rope | Metal Canteen | Right Handed | Red Bandana | Garlic Juice |
| Captain Avery | Brass Telescope | Smoky Torch | Right Handed | Green Bandana | Garlic Juice |
| Olivia Oakley | Brass Telescope | Canvas Sack | Right Handed | Blue Bandana | Citrus Spray |
| Jasper Jones | Grappling Hook | Bamboo Whistle | Left Handed | Blue Bandana | Citrus Spray |
| Sierra Stone | Grappling Hook | Canvas Sack | Right Handed | Green Bandana | Garlic Juice |
| Xander Yates | Climbing Rope | Smoky Torch | Right Handed | Blue Bandana | Citrus Spray |
| Georgia Gale | Grappling Hook | Smoky Torch | Left Handed | Red Bandana | Citrus Spray |
| Quinn Reed | Brass Telescope | Canvas Sack | Left Handed | Blue Bandana | Peppermint Oil |
| Isla Irving | Jungle Machete | Signal Flare | Right Handed | Red Bandana | Garlic Juice |
| Vince Vance | Brass Telescope | Signal Flare | Right Handed | Green Bandana | Peppermint Oil |
| Piper Parker | Pocket Compass | Bamboo Whistle | Right Handed | Green Bandana | Garlic Juice |
| Leo Lawson | Climbing Rope | Metal Canteen | Left Handed | Green Bandana | Garlic Juice |
| Maya Miller | Pocket Compass | Metal Canteen | Left Handed | Red Bandana | Peppermint Oil |
| Toby Turner | Climbing Rope | Signal Flare | Right Handed | Red Bandana | Peppermint Oil |
| Barnaby Blake | Brass Telescope | Signal Flare | Right Handed | Red Bandana | Citrus Spray |
| Nico Nelson | Climbing Rope | Canvas Sack | Left Handed | Red Bandana | Citrus Spray |
| Coralia Cruz | Jungle Machete | Canvas Sack | Left Handed | Red Bandana | Citrus Spray |
| Drake Dawson | Pocket Compass | Canvas Sack | Left Handed | Blue Bandana | Citrus Spray |
| Finn Foster | Grappling Hook | Metal Canteen | Left Handed | Red Bandana | Citrus Spray |
| Hector Hayes | Climbing Rope | Canvas Sack | Right Handed | Green Bandana | Peppermint Oil |
| Willa West | Jungle Machete | Metal Canteen | Left Handed | Red Bandana | Citrus Spray |
Clue 1
Rounding
The digital handheld scanner only shows rounded numbers when tracking camp gear.
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
2000
3700
7000
900
4300
700
700
300
4300
3000
130
370
7000
110
3000
370
T
2000
200
300
1100
1100
500
300
110
20
370
170
500
T
2000
370
1100
200
3700
Round 1,911 to the nearest thousandT
Round 167 to the nearest tenK
Round 4,284 to the nearest hundredI
Round 114 to the nearest tenS
Round 3,663 to the nearest hundredH
Round 507 to the nearest hundredY
Round 133 to the nearest tenD
Round 17 to the nearest tenM
Round 226 to the nearest hundredC
Round 726 to the nearest hundredL
Round 3,463 to the nearest thousandN
Round 942 to the nearest hundredV
Round 6,510 to the nearest thousandE
Round 374 to the nearest tenO
Round 1,105 to the nearest hundredR
Round 326 to the nearest hundredA
0/16 letters found
Clue 2
Addition
The search crew gathered and added all footprint records found along the muddy river.
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
8457
9347
4428
4730
6516
4380
8450
8450
8450
A
8457
9347
A
8457
5558
4380
3696
4730
8866
A
8457
6516
3518
4380
3518
8450
7970
8450
6750
4380
4712
4730
5511 + 2946 =A
2850 + 6016 =H
4585 + 3385 =U
6344 + 3003 =W
1558 + 2138 =F
3118 + 2440 =L
1832 + 1686 =D
2722 + 5728 =S
2543 + 1885 =I
3931 + 2819 =P
2790 + 1940 =T
2847 + 1533 =E
3596 + 2920 =N
1542 + 3170 =C
0/14 letters found
Clue 3
Subtraction
We compared the supply crate counts before and after the map went missing.
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
3621
5426
8626
T
3621
5426
5921
8626
2414
1028
6964
5333
5333
T
3621
5076
4172
4172
8626
5856
5901
4399
7261
5921
T
3621
2136
3038
5333
5333
4172
2136
6964
4399
6138 - 2517 =T
5060 - 661 =Y
11653 - 4689 =A
5084 - 2948 =R
9083 - 3750 =S
10391 - 4490 =B
5853 - 2815 =U
6196 - 2024 =P
9904 - 3983 =I
1591 - 563 =W
7835 - 574 =C
6762 - 4348 =F
8871 - 3015 =D
6842 - 1766 =O
9706 - 4280 =H
8728 - 102 =E
0/16 letters found
Clue 4
Multiplication facts (1-12)
The team arranged supply boxes into equal rows along the sandy shore.
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
3
72
45
72
T
36
72
99
T
36
35
56
72
9
30
80
5
45
90
72
45
42
121
5
45
121
5
121
9
35
42
72
90
28
9 × 4 =T
11 × 9 =C
8 × 10 =U
5 × 9 =D
7 × 8 =V
10 × 9 =R
11 × 11 =A
7 × 5 =I
7 × 4 =S
9 × 8 =E
1 × 5 =N
7 × 6 =B
6 × 5 =O
9 × 1 =F
1 × 3 =H
0/15 letters found
Clue 5
Division facts (1-12) — the last clue
The camp counselor split remaining lanterns equally among all search groups.
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
15 ÷ 5 = ?
16 ÷ 2 = ?
120 ÷ 12 = ?
32 ÷ 8 = ?
77 ÷ 11 = ?
11 ÷ 11 = ?
55 ÷ 11 = ?
48 ÷ 4 = ?
6 ÷ 1 = ?
14 ÷ 7 = ?
81 ÷ 9 = ?
Step 2 — cross out the sentence with each answer
1.The villain climbed up the ridge using a climbing rope, then took a long sip from a metal canteen.
2.The villain swung across the canyon using a grappling hook, then lit the dark path with a smoky torch.
3.The villain cleared thick branches using a jungle machete, then packed the stolen map into a canvas sack.
4.The villain scouted ahead using a brass telescope, then took a long sip from a metal canteen.
5.The villain cleared thick branches using a jungle machete, then lit the dark path with a smoky torch.
6.The villain swung across the canyon using a grappling hook, then signaled the crew with a signal flare.
7.The villain cleared thick branches using a jungle machete, then alerted birds with a bamboo whistle.
8.The villain cleared thick branches using a jungle machete, then took a long sip from a metal canteen.
9.The villain cleared thick branches using a jungle machete, then signaled the crew with a signal flare.
10.The villain swung across the canyon using a grappling hook, then took a long sip from a metal canteen.
11.The villain climbed up the ridge using a climbing rope, then packed the stolen map into a canvas sack.
12.The villain scouted ahead using a brass telescope, then packed the stolen map into a canvas sack.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Sapphire Island Map Mystery
Culprit: Nico Nelson (Climbing Rope · Canvas Sack · Left Handed · Red Bandana · Citrus Spray)
- Clue 1 (Rounding): "THE VILLAIN DOES NOT CARRY A SMOKY TORCH"Round 1,911 to the nearest thousand = 2000 (T) · Round 167 to the nearest ten = 170 (K) · Round 4,284 to the nearest hundred = 4300 (I) · Round 114 to the nearest ten = 110 (S) · Round 3,663 to the nearest hundred = 3700 (H) · Round 507 to the nearest hundred = 500 (Y) · Round 133 to the nearest ten = 130 (D) · Round 17 to the nearest ten = 20 (M) · Round 226 to the nearest hundred = 200 (C) · Round 726 to the nearest hundred = 700 (L) · Round 3,463 to the nearest thousand = 3000 (N) · Round 942 to the nearest hundred = 900 (V) · Round 6,510 to the nearest thousand = 7000 (E) · Round 374 to the nearest ten = 370 (O) · Round 1,105 to the nearest hundred = 1100 (R) · Round 326 to the nearest hundred = 300 (A)
- Clue 2 (Addition): "A WITNESS SAW A LEFT HANDED SUSPECT"5511 + 2946 = 8457 (A) · 2850 + 6016 = 8866 (H) · 4585 + 3385 = 7970 (U) · 6344 + 3003 = 9347 (W) · 1558 + 2138 = 3696 (F) · 3118 + 2440 = 5558 (L) · 1832 + 1686 = 3518 (D) · 2722 + 5728 = 8450 (S) · 2543 + 1885 = 4428 (I) · 3931 + 2819 = 6750 (P) · 2790 + 1940 = 4730 (T) · 2847 + 1533 = 4380 (E) · 3596 + 2920 = 6516 (N) · 1542 + 3170 = 4712 (C)
- Clue 3 (Subtraction): "THE THIEF WAS STOPPED BY CITRUS SPRAY"6138 - 2517 = 3621 (T) · 5060 - 661 = 4399 (Y) · 11653 - 4689 = 6964 (A) · 5084 - 2948 = 2136 (R) · 9083 - 3750 = 5333 (S) · 10391 - 4490 = 5901 (B) · 5853 - 2815 = 3038 (U) · 6196 - 2024 = 4172 (P) · 9904 - 3983 = 5921 (I) · 1591 - 563 = 1028 (W) · 7835 - 574 = 7261 (C) · 6762 - 4348 = 2414 (F) · 8871 - 3015 = 5856 (D) · 6842 - 1766 = 5076 (O) · 9706 - 4280 = 5426 (H) · 8728 - 102 = 8626 (E)
- Clue 4 (Multiplication facts (1-12)): "THE DETECTIVE FOUND RED BANDANA FIBERS"9 × 4 = 36 (T) · 11 × 9 = 99 (C) · 8 × 10 = 80 (U) · 5 × 9 = 45 (D) · 7 × 8 = 56 (V) · 10 × 9 = 90 (R) · 11 × 11 = 121 (A) · 7 × 5 = 35 (I) · 7 × 4 = 28 (S) · 9 × 8 = 72 (E) · 1 × 5 = 5 (N) · 7 × 6 = 42 (B) · 6 × 5 = 30 (O) · 9 × 1 = 9 (F) · 1 × 3 = 3 (H)
- Clue 5 (Division facts (1-12)): surviving statement (box 11) → Nico Nelson15 ÷ 5 = 3 · 16 ÷ 2 = 8 · 120 ÷ 12 = 10 · 32 ÷ 8 = 4 · 77 ÷ 11 = 7 · 11 ÷ 11 = 1 · 55 ÷ 11 = 5 · 48 ÷ 4 = 12 · 6 ÷ 1 = 6 · 14 ÷ 7 = 2 · 81 ÷ 9 = 9
About this mystery
- Grade level
- Grade 4 math
- Math topics
- Rounding, Addition, Subtraction, Multiplication, Division
- Reading level
- grades 3-4
- Theme
- The Sapphire Island Map Mystery — set in Sapphire Island Jungle Camp
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects