Grade 4Reading: grades 5-6Fractions of a numberMultiplicationPlace valueRounding
Mystery of the Sapphire Idol
The golden idol has been swiped from the central chamber! Deep inside the ruins, trail markers and broken traps reveal how the suspect moved through the ancient corridors.
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 | Gear Tool | Special Gadget | Dominant Hand | Hairstyle | Vulnerability |
|---|---|---|---|---|---|
| Digger Dan | smoke bomb | force shield | left handed | braided ponytail | bright sunlight |
| Scholar Sadie | climbing claws | force shield | left handed | slicked back | bright sunlight |
| Curator Cole | flash lantern | map compass | right handed | slicked back | bright sunlight |
| Professor Vance | grappling hook | ancient key | left handed | slicked back | bright sunlight |
| Navigator Nash | climbing claws | decoding lens | left handed | messy curls | bright sunlight |
| Surveyor Sam | grappling hook | decoding lens | right handed | braided ponytail | bright sunlight |
| Voyager Vince | smoke bomb | force shield | right handed | braided ponytail | loud gongs |
| Tracker Maya | climbing claws | ancient key | left handed | slicked back | loud gongs |
| Rover Ross | grappling hook | map compass | left handed | slicked back | bright sunlight |
| Pioneer Pete | grappling hook | ancient key | right handed | messy curls | loud gongs |
| Indiana Drake | jet boots | ancient key | right handed | messy curls | bright sunlight |
| Outrider Owen | flash lantern | decoding lens | right handed | slicked back | loud gongs |
| Dr Amelia Frost | climbing claws | force shield | right handed | messy curls | sticky honey |
| Lara Stone | grappling hook | force shield | right handed | messy curls | loud gongs |
| Scout Cooper | smoke bomb | sonic whistle | left handed | slicked back | bright sunlight |
| Captain Knox | smoke bomb | force shield | left handed | slicked back | bright sunlight |
| Agent Sterling | grappling hook | map compass | left handed | messy curls | sticky honey |
| Trekker Tess | grappling hook | sonic whistle | right handed | braided ponytail | loud gongs |
| Sleuth Skye | flash lantern | ancient key | left handed | messy curls | bright sunlight |
| Explorer Evie | flash lantern | decoding lens | left handed | messy curls | loud gongs |
| Hunter Hugo | jet boots | decoding lens | left handed | messy curls | sticky honey |
Clue 1
Fractions of a number
To decode the first vault door, we must calculate what fraction of the expedition supplies were recovered from the 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.
T
24
33
20
17
34
32
32
38
34
19
6
25
20
2
19
25
T
24
27
2
20
38
2
25
19
34
9
36
33
34
2
T
24
32
20
1/5 of 120 =T
6/8 of 48 =W
1/5 of 170 =I
2/6 of 75 =O
1/6 of 192 =L
6/8 of 12 =C
3/5 of 55 =H
6/8 of 8 =D
1/10 of 200 =E
2/6 of 6 =S
1/3 of 57 =N
1/6 of 102 =V
1/6 of 162 =U
2/8 of 152 =A
0/14 letters found
Clue 2
Multiplication facts (1-12)
The main tomb is lined with identical stone pillars set in matching rows and columns that we need to multiply.
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
45
50
80
70
120
49
6
6
6
A
45
50
70
25
49
22
81
77
35
36
80
70
81
6
49
77
49
99
70
25
A
45
120
21
9 × 5 =A
12 × 10 =N
5 × 5 =H
9 × 9 =U
1 × 6 =S
7 × 7 =E
10 × 7 =T
7 × 11 =L
8 × 10 =I
11 × 2 =C
9 × 11 =F
5 × 10 =W
9 × 4 =R
7 × 5 =P
7 × 3 =D
0/15 letters found
Clue 3
Place value
A secret stone dial requires setting the exact digit in the hundreds place to unlock the next secret passage.
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
400
3000
600
20
3000
300
200
90
4000
20
600
300
100
300
700
60
90
50
900
5000
90
6000
9000
400
T
30
600
4000
20
10
6000
9000
400
T
30
What is the value of the 3 in 431?T
What is the value of the 4 in 458?H
What is the value of the 7 in 765?Y
What is the value of the 3 in 306?A
What is the value of the 9 in 9,765?G
What is the value of the 6 in 6,734?I
What is the value of the 1 in 4,165?W
What is the value of the 9 in 935?M
What is the value of the 1 in 413?L
What is the value of the 6 in 2,863?F
What is the value of the 6 in 643?S
What is the value of the 4 in 64,965?U
What is the value of the 3 in 3,870?E
What is the value of the 5 in 7,259?O
What is the value of the 2 in 8,285?K
What is the value of the 9 in 3,791?R
What is the value of the 5 in 5,983?B
What is the value of the 2 in 6,124?N
0/18 letters found
Clue 4
Rounding
The ancient altitude gauge only gives approximate heights, so we must round the distances to the nearest hundred.
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
1300
170
30
300
370
290
170
300
S
1300
500
110
2000
5000
1100
S
1300
200
90
370
2900
170
1100
9000
30
370
2900
290
30
90
300
30
20
S
1300
370
170
5000
170
Round 1,333 to the nearest hundredS
Round 31 to the nearest tenA
Round 8,646 to the nearest thousandB
Round 24 to the nearest tenT
Round 539 to the nearest hundredF
Round 369 to the nearest tenC
Round 2,889 to the nearest hundredK
Round 112 to the nearest tenO
Round 344 to the nearest hundredR
Round 293 to the nearest tenH
Round 86 to the nearest tenI
Round 5,415 to the nearest thousandN
Round 173 to the nearest tenE
Round 200 to the nearest hundredL
Round 1,983 to the nearest thousandU
Round 1,096 to the nearest hundredD
0/16 letters found
Clue 5
Fractions of a number — the last clue
We found a broken map divided into equal parchment scraps, and calculating the remaining fraction reveals our 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
1/5 of 45 = ?
3/10 of 10 = ?
1/4 of 44 = ?
1/5 of 50 = ?
1/6 of 30 = ?
5/10 of 16 = ?
1/4 of 28 = ?
1/10 of 120 = ?
1/4 of 4 = ?
2/4 of 8 = ?
4/10 of 15 = ?
Step 2 — cross out the sentence with each answer
1.The villain swung across the canyon with a grappling hook, then scanned the stone tiles with a decoding lens.
2.The villain swung across the canyon with a grappling hook, then unlocked the vault using an ancient key.
3.The villain scaled the stone temple using climbing claws, then blocked the dart traps using a force shield.
4.The villain zipped over the pit using jet boots, then unlocked the vault using an ancient key.
5.The villain zipped over the pit using jet boots, then navigated the maze with a map compass.
6.The villain vanished into thin air using a smoke bomb, then navigated the maze with a map compass.
7.The villain swung across the canyon with a grappling hook, then blocked the dart traps using a force shield.
8.The villain blinded the guards with a flash lantern, then unlocked the vault using an ancient key.
9.The villain swung across the canyon with a grappling hook, then navigated the maze with a map compass.
10.The villain vanished into thin air using a smoke bomb, then signaled the camp using a sonic whistle.
11.The villain vanished into thin air using a smoke bomb, then blocked the dart traps using a force shield.
12.The villain blinded the guards with a flash lantern, then blocked the dart traps using a force shield.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — Mystery of the Sapphire Idol
Culprit: Professor Vance (grappling hook · ancient key · left handed · slicked back · bright sunlight)
- Clue 1 (Fractions of a number): "THE VILLAIN DOES NOT USE A SONIC WHISTLE"1/5 of 120 = 24 (T) · 6/8 of 48 = 36 (W) · 1/5 of 170 = 34 (I) · 2/6 of 75 = 25 (O) · 1/6 of 192 = 32 (L) · 6/8 of 12 = 9 (C) · 3/5 of 55 = 33 (H) · 6/8 of 8 = 6 (D) · 1/10 of 200 = 20 (E) · 2/6 of 6 = 2 (S) · 1/3 of 57 = 19 (N) · 1/6 of 102 = 17 (V) · 1/6 of 162 = 27 (U) · 2/8 of 152 = 38 (A)
- Clue 2 (Multiplication facts (1-12)): "A WITNESS SAW THE CULPRIT USE LEFT HAND"9 × 5 = 45 (A) · 12 × 10 = 120 (N) · 5 × 5 = 25 (H) · 9 × 9 = 81 (U) · 1 × 6 = 6 (S) · 7 × 7 = 49 (E) · 10 × 7 = 70 (T) · 7 × 11 = 77 (L) · 8 × 10 = 80 (I) · 11 × 2 = 22 (C) · 9 × 11 = 99 (F) · 5 × 10 = 50 (W) · 9 × 4 = 36 (R) · 7 × 5 = 35 (P) · 7 × 3 = 21 (D)
- Clue 3 (Place value): "THE SNEAK RUNS AWAY FROM BRIGHT SUNLIGHT"What is the value of the 3 in 431? = 30 (T) · What is the value of the 4 in 458? = 400 (H) · What is the value of the 7 in 765? = 700 (Y) · What is the value of the 3 in 306? = 300 (A) · What is the value of the 9 in 9,765? = 9000 (G) · What is the value of the 6 in 6,734? = 6000 (I) · What is the value of the 1 in 4,165? = 100 (W) · What is the value of the 9 in 935? = 900 (M) · What is the value of the 1 in 413? = 10 (L) · What is the value of the 6 in 2,863? = 60 (F) · What is the value of the 6 in 643? = 600 (S) · What is the value of the 4 in 64,965? = 4000 (U) · What is the value of the 3 in 3,870? = 3000 (E) · What is the value of the 5 in 7,259? = 50 (O) · What is the value of the 2 in 8,285? = 200 (K) · What is the value of the 9 in 3,791? = 90 (R) · What is the value of the 5 in 5,983? = 5000 (B) · What is the value of the 2 in 6,124? = 20 (N)
- Clue 4 (Rounding): "SEARCHERS FOUND SLICKED BACK HAIR AT SCENE"Round 1,333 to the nearest hundred = 1300 (S) · Round 31 to the nearest ten = 30 (A) · Round 8,646 to the nearest thousand = 9000 (B) · Round 24 to the nearest ten = 20 (T) · Round 539 to the nearest hundred = 500 (F) · Round 369 to the nearest ten = 370 (C) · Round 2,889 to the nearest hundred = 2900 (K) · Round 112 to the nearest ten = 110 (O) · Round 344 to the nearest hundred = 300 (R) · Round 293 to the nearest ten = 290 (H) · Round 86 to the nearest ten = 90 (I) · Round 5,415 to the nearest thousand = 5000 (N) · Round 173 to the nearest ten = 170 (E) · Round 200 to the nearest hundred = 200 (L) · Round 1,983 to the nearest thousand = 2000 (U) · Round 1,096 to the nearest hundred = 1100 (D)
- Clue 5 (Fractions of a number): surviving statement (box 2) → Professor Vance1/5 of 45 = 9 · 3/10 of 10 = 3 · 1/4 of 44 = 11 · 1/5 of 50 = 10 · 1/6 of 30 = 5 · 5/10 of 16 = 8 · 1/4 of 28 = 7 · 1/10 of 120 = 12 · 1/4 of 4 = 1 · 2/4 of 8 = 4 · 4/10 of 15 = 6
About this mystery
- Grade level
- Grade 4 math
- Math topics
- Fractions of a number, Multiplication, Place value, Rounding
- Reading level
- grades 5-6
- Theme
- Mystery of the Sapphire Idol — set in The Lost Temple of Sapphire Peak
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects