Grade 9Reading: grades 7-9AdditionSubtractionMultiplicationRoundingDivision
The Lost Astrolabe of Skylandia
The ancient Golden Astrolabe has been stolen from the Grand Library of Skylandia! A rogue captain slipped through the clouds, bypassed the clockwork security, and fled into the sky. You, the lead Sky-Detective, must track them down.
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 | Specialty Tool | Invention | Suspect's Gear | Hair Color | Suspect's Flaw |
|---|---|---|---|---|---|
| Xavier Frost | decoder-ring champion | decoy balloon | wearing a leather scarf | dusty brown hair | distracted by shiny coins |
| Hudson Hawk | lock-pick genius | decoy balloon | wearing a leather scarf | dusty brown hair | allergic to cloud-lilies |
| Jasper Flint | glider-suit master | double-jump boots | wearing a leather scarf | jet black hair | allergic to cloud-lilies |
| Sabin Drake | grappling-hook expert | double-jump boots | wearing a leather scarf | bright red hair | allergic to cloud-lilies |
| Zelda Smith | decoder-ring champion | cloud-camouflage suit | wearing brass goggles | bright red hair | allergic to cloud-lilies |
| Flynn Ryder | smoke-bomb specialist | cloud-camouflage suit | wearing a leather scarf | dusty brown hair | afraid of heights |
| Victor Sullivan | glider-suit master | pocket compass | wearing a leather scarf | bright red hair | allergic to cloud-lilies |
| Penelope Cruz | lock-pick genius | cloud-camouflage suit | wearing brass goggles | dusty brown hair | allergic to cloud-lilies |
| Tessa Croft | glider-suit master | cloud-camouflage suit | wearing brass goggles | bright red hair | allergic to cloud-lilies |
| Wyatt Earp | smoke-bomb specialist | pocket compass | wearing a leather scarf | dusty brown hair | allergic to cloud-lilies |
| Luna Sterling | glider-suit master | pocket compass | wearing brass goggles | dusty brown hair | distracted by shiny coins |
| Quincy Morris | grappling-hook expert | double-jump boots | wearing a leather scarf | dusty brown hair | allergic to cloud-lilies |
| Clara Barton | smoke-bomb specialist | double-jump boots | wearing a leather scarf | jet black hair | allergic to cloud-lilies |
| Gemma Stone | smoke-bomb specialist | magnetic gloves | wearing a leather scarf | dusty brown hair | allergic to cloud-lilies |
| Barnaby Jones | lock-pick genius | magnetic gloves | wearing brass goggles | dusty brown hair | distracted by shiny coins |
| Marcus Brody | lock-pick genius | double-jump boots | wearing brass goggles | dusty brown hair | distracted by shiny coins |
| Orville Wright | grappling-hook expert | decoy balloon | wearing brass goggles | jet black hair | distracted by shiny coins |
| Kit Carson | grappling-hook expert | pocket compass | wearing a leather scarf | dusty brown hair | allergic to cloud-lilies |
| Nellie Bly | lock-pick genius | decoy balloon | wearing brass goggles | dusty brown hair | afraid of heights |
| Drake Vance | decoder-ring champion | pocket compass | wearing a leather scarf | dusty brown hair | distracted by shiny coins |
| Ruby Roundhouse | decoder-ring champion | cloud-camouflage suit | wearing a leather scarf | dusty brown hair | afraid of heights |
Clue 1
Addition
We found a scattered logbook. Adding up the torn-out pages gives us a starting point to track our suspect's flight 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
4626
9743
4859
7206
9382
7206
8238
4859
6272
T
4626
3084
7919
4859
7206
8191
7919
T
4626
9382
7206
4859
3575
3084
4859
6272
7919
5313
8443
3575
7492
7492
7919
7919
8191
2525 + 2101 =T
2612 + 3660 =C
4486 + 3433 =O
2884 + 5559 =B
6265 + 3117 =U
5328 + 2863 =N
4264 + 5479 =H
3255 + 1604 =E
2585 + 4907 =L
3027 + 4179 =S
2604 + 2709 =Y
2091 + 993 =D
4314 + 3924 =P
2077 + 1498 =A
0/14 letters found
Clue 2
Subtraction
The runaway airship is dropping ballast weight to climb higher. Subtracting the discarded iron crates reveals their current engine strain.
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
2141
3846
3877
6478
6478
8980
1401
6478
3877
5319
7310
3600
3877
4803
S
2141
8297
5319
4803
1401
8220
3538
7310
3600
3877
8297
5319
1444
8220
3538
3019 - 878 =S
8588 - 3269 =A
5104 - 1566 =N
4568 - 3124 =B
8423 - 3620 =R
13162 - 4865 =C
13014 - 4794 =I
1545 - 144 =F
12098 - 4788 =T
8595 - 4749 =M
7063 - 3186 =E
8268 - 1790 =L
9410 - 430 =O
6494 - 2894 =H
0/14 letters found
Clue 3
Multiplication facts (1-12)
To decode the vault's secondary lock, we must multiply the rows of spinning brass gear teeth inside the control panel.
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
66
27
81
30
24
88
88
42
24
45
120
45
81
81
63
81
48
45
81
42
77
T
66
27
81
55
88
96
12
81
77
120
11 × 6 =T
3 × 10 =V
1 × 12 =W
10 × 12 =S
9 × 9 =E
7 × 6 =A
11 × 5 =F
3 × 9 =H
9 × 7 =Z
4 × 12 =D
8 × 11 =L
8 × 12 =O
5 × 9 =N
3 × 8 =I
11 × 7 =R
0/15 letters found
Clue 4
Rounding
Our long-range radar is fuzzy due to the cloud storm. Rounding the scrambled static signals to the nearest hundred pinpoints the suspect's location.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
F
900
90
700
20
430
430
700
230
370
4300
1300
110
90
500
20
30
3000
50
110
90
20
370
30
1700
30
1700
3700
2000
Round 894 to the nearest hundredF
Round 1,741 to the nearest hundredE
Round 2,654 to the nearest thousandA
Round 433 to the nearest tenD
Round 109 to the nearest tenR
Round 27 to the nearest tenH
Round 4,297 to the nearest hundredY
Round 454 to the nearest hundredW
Round 92 to the nearest tenO
Round 2,404 to the nearest thousandM
Round 716 to the nearest hundredU
Round 20 to the nearest tenN
Round 231 to the nearest tenS
Round 1,331 to the nearest hundredB
Round 46 to the nearest tenI
Round 3,688 to the nearest hundredL
Round 373 to the nearest tenT
0/17 letters found
Clue 5
Division facts (1-12) — the last clue
The crew must share the remaining sky-fuel canisters equally among the chase ships. Dividing the canisters shows us how far our fleet can go.
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
2 ÷ 1 = ?
64 ÷ 8 = ?
6 ÷ 2 = ?
4 ÷ 4 = ?
33 ÷ 3 = ?
20 ÷ 2 = ?
45 ÷ 9 = ?
90 ÷ 10 = ?
84 ÷ 12 = ?
36 ÷ 3 = ?
48 ÷ 8 = ?
Step 2 — cross out the sentence with each answer
1.The villain unlocked the secure display case, then escaped in a steam-powered glider.
2.The villain sneaked past the clockwork guards, then fled into the thick fog.
3.The villain swung across the sky-dock, then dropped down a secret trapdoor.
4.The villain swung across the sky-dock, then zipped away on a sky-line.
5.The villain soared through the clouds, then fled into the thick fog.
6.The villain unlocked the secure display case, then dropped down a secret trapdoor.
7.The villain unlocked the secure display case, then fled into the thick fog.
8.The villain sneaked past the clockwork guards, then zipped away on a sky-line.
9.The villain sneaked past the clockwork guards, then slipped into the cargo hold.
10.The villain decoded the vault door locks, then dropped down a secret trapdoor.
11.The villain sneaked past the clockwork guards, then dropped down a secret trapdoor.
12.The villain decoded the vault door locks, then escaped in a steam-powered glider.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Lost Astrolabe of Skylandia
Culprit: Kit Carson (grappling-hook expert · pocket compass · wearing a leather scarf · dusty brown hair · allergic to cloud-lilies)
- Clue 1 (Addition): "THE SUSPECT DOES NOT USE A DECOY BALLOON"2525 + 2101 = 4626 (T) · 2612 + 3660 = 6272 (C) · 4486 + 3433 = 7919 (O) · 2884 + 5559 = 8443 (B) · 6265 + 3117 = 9382 (U) · 5328 + 2863 = 8191 (N) · 4264 + 5479 = 9743 (H) · 3255 + 1604 = 4859 (E) · 2585 + 4907 = 7492 (L) · 3027 + 4179 = 7206 (S) · 2604 + 2709 = 5313 (Y) · 2091 + 993 = 3084 (D) · 4314 + 3924 = 8238 (P) · 2077 + 1498 = 3575 (A)
- Clue 2 (Subtraction): "SMELL OF LEATHER SCARF IN THE CABIN"3019 - 878 = 2141 (S) · 8588 - 3269 = 5319 (A) · 5104 - 1566 = 3538 (N) · 4568 - 3124 = 1444 (B) · 8423 - 3620 = 4803 (R) · 13162 - 4865 = 8297 (C) · 13014 - 4794 = 8220 (I) · 1545 - 144 = 1401 (F) · 12098 - 4788 = 7310 (T) · 8595 - 4749 = 3846 (M) · 7063 - 3186 = 3877 (E) · 8268 - 1790 = 6478 (L) · 9410 - 430 = 8980 (O) · 6494 - 2894 = 3600 (H)
- Clue 3 (Multiplication facts (1-12)): "THE VILLAIN SNEEZED NEAR THE FLOWERS"11 × 6 = 66 (T) · 3 × 10 = 30 (V) · 1 × 12 = 12 (W) · 10 × 12 = 120 (S) · 9 × 9 = 81 (E) · 7 × 6 = 42 (A) · 11 × 5 = 55 (F) · 3 × 9 = 27 (H) · 9 × 7 = 63 (Z) · 4 × 12 = 48 (D) · 8 × 11 = 88 (L) · 8 × 12 = 96 (O) · 5 × 9 = 45 (N) · 3 × 8 = 24 (I) · 11 × 7 = 77 (R)
- Clue 4 (Rounding): "FOUND DUSTY BROWN HAIR ON THE HELM"Round 894 to the nearest hundred = 900 (F) · Round 1,741 to the nearest hundred = 1700 (E) · Round 2,654 to the nearest thousand = 3000 (A) · Round 433 to the nearest ten = 430 (D) · Round 109 to the nearest ten = 110 (R) · Round 27 to the nearest ten = 30 (H) · Round 4,297 to the nearest hundred = 4300 (Y) · Round 454 to the nearest hundred = 500 (W) · Round 92 to the nearest ten = 90 (O) · Round 2,404 to the nearest thousand = 2000 (M) · Round 716 to the nearest hundred = 700 (U) · Round 20 to the nearest ten = 20 (N) · Round 231 to the nearest ten = 230 (S) · Round 1,331 to the nearest hundred = 1300 (B) · Round 46 to the nearest ten = 50 (I) · Round 3,688 to the nearest hundred = 3700 (L) · Round 373 to the nearest ten = 370 (T)
- Clue 5 (Division facts (1-12)): surviving statement (box 4) → Kit Carson2 ÷ 1 = 2 · 64 ÷ 8 = 8 · 6 ÷ 2 = 3 · 4 ÷ 4 = 1 · 33 ÷ 3 = 11 · 20 ÷ 2 = 10 · 45 ÷ 9 = 5 · 90 ÷ 10 = 9 · 84 ÷ 12 = 7 · 36 ÷ 3 = 12 · 48 ÷ 8 = 6
About this mystery
- Grade level
- Grade 9 math
- Math topics
- Addition, Subtraction, Multiplication, Rounding, Division
- Reading level
- grades 7-9
- Theme
- The Lost Astrolabe of Skylandia — set in The Windward Isles, a floating archipelago of sky islands
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects