Grade 8Reading: grades 7-9AdditionMultiplicationRoundingWord problemsDivision
The Mystery of the Sunken Citadel
Someone broke into the Echo Jungle excavation headquarters and stole the golden Sun Codex! The lead archaeologist needs your help to examine the evidence, decode the suspect list, and identify the thief.
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 | Primary Gear | Field Skill | Footwear | Hairstyle | Countermeasure |
|---|---|---|---|---|---|
| Marcus Thorne | grapple hook | rope climbing | wearing boots | ponytail hair | smoke bombs |
| Lily Montgomery | grapple hook | map drawing | wearing boots | ponytail hair | bright flares |
| Sophia Ruiz | sonar scanner | lock picking | wearing boots | ponytail hair | bright flares |
| Jordan Hayes | grapple hook | deciphering runes | wearing boots | ponytail hair | smoke bombs |
| Alex Vance | grapple hook | lock picking | wearing boots | ponytail hair | smoke bombs |
| Ethan Hunt | laser cutter | lock picking | wearing boots | braided hair | bright flares |
| Olivia Sterling | grapple hook | lock picking | wearing sneakers | ponytail hair | smoke bombs |
| Benjamin Cole | signal jammer | rope climbing | wearing boots | ponytail hair | smoke bombs |
| Maya Lin | signal jammer | deciphering runes | wearing boots | braided hair | loud whistles |
| Hannah Abbott | grapple hook | deciphering runes | wearing boots | braided hair | smoke bombs |
| Mia Tanaka | grapple hook | artifact restoration | wearing boots | ponytail hair | bright flares |
| Noah Sinclair | signal jammer | lock picking | wearing boots | ponytail hair | loud whistles |
| Nina Patel | laser cutter | artifact restoration | wearing boots | ponytail hair | loud whistles |
| Chloe Bennett | sonar scanner | map drawing | wearing boots | ponytail hair | smoke bombs |
| Mateo Gomez | signal jammer | map drawing | wearing sneakers | braided hair | bright flares |
| Elena Rostova | sonar scanner | map drawing | wearing boots | buzzed hair | loud whistles |
| Ava Rhodes | thermal visor | rope climbing | wearing sneakers | braided hair | loud whistles |
| Carter Cruz | sonar scanner | map drawing | wearing sneakers | ponytail hair | smoke bombs |
| David Zhang | sonar scanner | rope climbing | wearing sneakers | ponytail hair | bright flares |
| Samuel Oaks | laser cutter | artifact restoration | wearing boots | buzzed hair | bright flares |
| Zoe Brooks | signal jammer | artifact restoration | wearing boots | ponytail hair | bright flares |
Clue 1
Addition
To recover the scout logs, tally up the total number of recovered journal pages across all sector teams.
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
3211
7065
8502
8376
7325
6001
6001
5858
7325
2961
3313
4718
8502
3540
2961
4718
T
3211
2414
3540
8502
6001
4718
3985
4624
4025
7325
3985
4624
7325
2961
5482
1620 + 1591 =T
2060 + 1965 =P
4028 + 3037 =H
3644 + 4732 =V
3087 + 2771 =A
2486 + 1499 =C
2830 + 3171 =L
2813 + 5689 =E
1501 + 1460 =N
2841 + 1783 =K
1084 + 1330 =U
2454 + 3028 =G
2954 + 1764 =O
1409 + 2131 =S
4242 + 3083 =I
2042 + 1271 =D
0/16 letters found
Clue 2
Multiplication facts (1-12)
Each expedition crate holds multiple supplies, so calculate the total weight across all packed crates.
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
1
63
8
T
1
63
2
8
5
80
8
5
T
1
18
8
8
108
30
90
90
T
1
108
88
2
54
T
1
55
2
54
56
28
18
1 × 1 =T
8 × 10 =L
11 × 5 =S
9 × 10 =O
7 × 9 =H
7 × 8 =M
4 × 7 =U
6 × 9 =N
5 × 6 =B
6 × 3 =D
8 × 11 =R
1 × 2 =I
9 × 12 =P
2 × 4 =E
5 × 1 =F
0/15 letters found
Clue 3
Rounding
The vault radar system gives approximate distance readings, so round each scan entry to the nearest hundred meters.
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
9000
170
370
200
90
7000
500
2900
T
9000
170
500
370
4300
7000
2000
230
1300
290
370
3000
1300
230
3000
T
9000
1300
500
370
T
9000
500
370
7000
T
9000
Round 9,399 to the nearest thousandT
Round 2,916 to the nearest hundredD
Round 231 to the nearest tenM
Round 166 to the nearest tenH
Round 1,676 to the nearest thousandS
Round 4,308 to the nearest hundredW
Round 368 to the nearest tenE
Round 243 to the nearest hundredG
Round 293 to the nearest tenK
Round 7,066 to the nearest thousandA
Round 1,304 to the nearest hundredO
Round 3,234 to the nearest thousandB
Round 89 to the nearest tenU
Round 509 to the nearest hundredR
0/14 letters found
Clue 4
Word problems
Solve these field report story problems to unlock the ciphered coordinates for the next clue.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Astrandof hairturnedupatthescene.
P
35
56
16
30
88
74
85
L
H
74
85
R
Scout lined up 7 rows of 5 carabiner. How many carabiner in all?P
Scout lined up 7 rows of 8 canteen. How many canteen in all?O
There were 43 carabiner. 27 were used up. How many carabiner are left?N
Scout lined up 6 rows of 5 compass. How many compass in all?Y
There were 116 tarp. 31 were used up. How many tarp are left?I
Scout found 22 canteen yesterday and 52 more today. How many canteen in all?A
There were 125 tarp. 37 were used up. How many tarp are left?T
0/7 letters found
Clue 5
Division facts (1-12) — the last clue
Split the expedition emergency rations equally among the research teams to determine each team share.
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 = ?
72 ÷ 12 = ?
12 ÷ 12 = ?
40 ÷ 8 = ?
72 ÷ 6 = ?
81 ÷ 9 = ?
22 ÷ 11 = ?
56 ÷ 8 = ?
33 ÷ 3 = ?
12 ÷ 3 = ?
110 ÷ 11 = ?
Step 2 — cross out the sentence with each answer
1.The villain fired a grapple hook to scale the wall, then climbed down the cliff rope.
2.The villain activated a sonar scanner to ping the vault, then picked the vault lock.
3.The villain fired a grapple hook to scale the wall, then deciphered ancient runes on the arch.
4.The villain used a laser cutter to slice the door, then climbed down the cliff rope.
5.The villain turned on a signal jammer to disable security, then sketched a map of the hidden tunnels.
6.The villain activated a sonar scanner to ping the vault, then sketched a map of the hidden tunnels.
7.The villain fired a grapple hook to scale the wall, then picked the vault lock.
8.The villain turned on a signal jammer to disable security, then climbed down the cliff rope.
9.The villain used a laser cutter to slice the door, then sketched a map of the hidden tunnels.
10.The villain turned on a signal jammer to disable security, then picked the vault lock.
11.The villain switched on a thermal visor to see in the dark, then picked the vault lock.
12.The villain fired a grapple hook to scale the wall, then sketched a map of the hidden tunnels.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of the Sunken Citadel
Culprit: Benjamin Cole (signal jammer · rope climbing · wearing boots · ponytail hair · smoke bombs)
- Clue 1 (Addition): "THE VILLAIN DOES NOT USE LOCK PICKING"1620 + 1591 = 3211 (T) · 2060 + 1965 = 4025 (P) · 4028 + 3037 = 7065 (H) · 3644 + 4732 = 8376 (V) · 3087 + 2771 = 5858 (A) · 2486 + 1499 = 3985 (C) · 2830 + 3171 = 6001 (L) · 2813 + 5689 = 8502 (E) · 1501 + 1460 = 2961 (N) · 2841 + 1783 = 4624 (K) · 1084 + 1330 = 2414 (U) · 2454 + 3028 = 5482 (G) · 2954 + 1764 = 4718 (O) · 1409 + 2131 = 3540 (S) · 4242 + 3083 = 7325 (I) · 2042 + 1271 = 3313 (D)
- Clue 2 (Multiplication facts (1-12)): "THE THIEF LEFT DEEP BOOT PRINTS IN MUD"1 × 1 = 1 (T) · 8 × 10 = 80 (L) · 11 × 5 = 55 (S) · 9 × 10 = 90 (O) · 7 × 9 = 63 (H) · 7 × 8 = 56 (M) · 4 × 7 = 28 (U) · 6 × 9 = 54 (N) · 5 × 6 = 30 (B) · 6 × 3 = 18 (D) · 8 × 11 = 88 (R) · 1 × 2 = 2 (I) · 9 × 12 = 108 (P) · 2 × 4 = 8 (E) · 5 × 1 = 5 (F)
- Clue 3 (Rounding): "THE GUARD THREW A SMOKE BOMB TO RETREAT"Round 9,399 to the nearest thousand = 9000 (T) · Round 2,916 to the nearest hundred = 2900 (D) · Round 231 to the nearest ten = 230 (M) · Round 166 to the nearest ten = 170 (H) · Round 1,676 to the nearest thousand = 2000 (S) · Round 4,308 to the nearest hundred = 4300 (W) · Round 368 to the nearest ten = 370 (E) · Round 243 to the nearest hundred = 200 (G) · Round 293 to the nearest ten = 290 (K) · Round 7,066 to the nearest thousand = 7000 (A) · Round 1,304 to the nearest hundred = 1300 (O) · Round 3,234 to the nearest thousand = 3000 (B) · Round 89 to the nearest ten = 90 (U) · Round 509 to the nearest hundred = 500 (R)
- Clue 4 (Word problems): "PONYTAIL HAIR"Scout lined up 7 rows of 5 carabiner. How many carabiner in all? = 35 (P) · Scout lined up 7 rows of 8 canteen. How many canteen in all? = 56 (O) · There were 43 carabiner. 27 were used up. How many carabiner are left? = 16 (N) · Scout lined up 6 rows of 5 compass. How many compass in all? = 30 (Y) · There were 116 tarp. 31 were used up. How many tarp are left? = 85 (I) · Scout found 22 canteen yesterday and 52 more today. How many canteen in all? = 74 (A) · There were 125 tarp. 37 were used up. How many tarp are left? = 88 (T)
- Clue 5 (Division facts (1-12)): surviving statement (box 8) → Benjamin Cole15 ÷ 5 = 3 · 72 ÷ 12 = 6 · 12 ÷ 12 = 1 · 40 ÷ 8 = 5 · 72 ÷ 6 = 12 · 81 ÷ 9 = 9 · 22 ÷ 11 = 2 · 56 ÷ 8 = 7 · 33 ÷ 3 = 11 · 12 ÷ 3 = 4 · 110 ÷ 11 = 10
About this mystery
- Grade level
- Grade 8 math
- Math topics
- Addition, Multiplication, Rounding, Word problems, Division
- Reading level
- grades 7-9
- Theme
- The Mystery of the Sunken Citadel — set in Echo Jungle Explorer Camp
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects