🔎 Stranger ThingsGrade 6Reading: grades 3-4MultiplicationMulti-step word problemsPercentagesExponentsMissing addends

The Mystery of Echo Ridge

A strange power surge hit the Echo Ridge arcade and opened a portal to a shadowy dimension! A mysterious monster snatched the arcade manager and disappeared into the fog. The local radio club must track down clues to save the town.

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	Extra Power	Dominant Hand	Hair Style	Weakness
Nancy Wheeler	time echo	sound wave	LEFT HANDED	CURLY MESH	BRIGHT FLASHLIGHT
Will Byers	portal spark	gravity flip	RIGHT HANDED	CURLY MESH	LOUD ROCK MUSIC
Mikey Wheeler	mind pulse	frost touch	RIGHT HANDED	SPIKY CUT	LOUD ROCK MUSIC
Erica Sinclair	telekinesis	sound wave	LEFT HANDED	CURLY MESH	BRIGHT FLASHLIGHT
Max Mayfield	telekinesis	frost touch	RIGHT HANDED	BUZZ CUT	LOUD ROCK MUSIC
Bob Newby	telekinesis	static shield	LEFT HANDED	CURLY MESH	BRIGHT FLASHLIGHT
Robin Buckley	mind pulse	sound wave	LEFT HANDED	BUZZ CUT	LOUD ROCK MUSIC
Eleven Hopper	shadow cloak	laser glance	LEFT HANDED	CURLY MESH	BRIGHT FLASHLIGHT
Steve Harrington	telekinesis	laser glance	LEFT HANDED	CURLY MESH	STICKY HAIRSPRAY
Chrissy Cunningham	telekinesis	sound wave	RIGHT HANDED	SPIKY CUT	LOUD ROCK MUSIC
Argyle	telekinesis	frost touch	LEFT HANDED	SPIKY CUT	LOUD ROCK MUSIC
Suzie Bingham	time echo	laser glance	RIGHT HANDED	SPIKY CUT	BRIGHT FLASHLIGHT
Jim Hopper	mind pulse	laser glance	LEFT HANDED	BUZZ CUT	STICKY HAIRSPRAY
Eddie Munson	telekinesis	laser glance	LEFT HANDED	BUZZ CUT	BRIGHT FLASHLIGHT
Joyce Byers	shadow cloak	static shield	RIGHT HANDED	CURLY MESH	BRIGHT FLASHLIGHT
Karen Wheeler	mind pulse	sound wave	RIGHT HANDED	BUZZ CUT	STICKY HAIRSPRAY
Billy Hargrove	mind pulse	gravity flip	LEFT HANDED	BUZZ CUT	STICKY HAIRSPRAY
Dr Owens	time echo	laser glance	RIGHT HANDED	CURLY MESH	BRIGHT FLASHLIGHT
Dustin Henderson	telekinesis	frost touch	LEFT HANDED	CURLY MESH	BRIGHT FLASHLIGHT
Lucas Sinclair	mind pulse	gravity flip	LEFT HANDED	BUZZ CUT	LOUD ROCK MUSIC
Fred Benson	portal spark	laser glance	RIGHT HANDED	BUZZ CUT	STICKY HAIRSPRAY

Clue 1

Multiplication facts (1-12)

You check the rows of walkie talkies charging on the lab workbench to gather your first 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.

132

100

108

121

100

121

132

100

144

121

132

121

12 × 11 =T

1 × 1 =I

12 × 9 =L

7 × 11 =V

1 × 2 =U

2 × 8 =S

10 × 10 =E

4 × 9 =R

8 × 8 =N

6 × 7 =H

3 × 11 =C

3 × 1 =D

12 × 12 =F

11 × 11 =O

7 × 8 =A

0/15 letters found

Clue 2

Multi-step word problems

The team counts the arcade tokens collected before and after the surge to calculate the damage.

Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.

Awitnesssawthevillainwas

There were 242 waffles in all. 1 The Hawkins Radio Club used 12 waffles each. The other 5 The Hawkins Radio Club shared the rest equally. How many waffles did each of the other The Hawkins Radio Club get?L

AV Club Detective earned 6 walkie talkies in each of 2 rounds, plus 10 bonus walkie talkies. Then 6 walkie talkies were lost. How many walkie talkies are left?T

There were 95 twenty sided dice in all. 4 The Hawkins Radio Club used 14 twenty sided dice each. The other 3 The Hawkins Radio Club shared the rest equally. How many twenty sided dice did each of the other The Hawkins Radio Club get?N

There were 264 walkie talkies in all. 21 walkie talkies were set aside. The rest were shared equally among 3 The Hawkins Radio Club. How many walkie talkies did each get?E

There were 304 flashlights in all. 1 The Hawkins Radio Club used 28 flashlights each. The other 4 The Hawkins Radio Club shared the rest equally. How many flashlights did each of the other The Hawkins Radio Club get?A

There were 49 flashlights in all. 29 flashlights were set aside. The rest were shared equally among 2 The Hawkins Radio Club. How many flashlights did each get?F

AV Club Detective collected 2 flashlights in the morning and 262 flashlights in the afternoon, then split them equally among 4 The Hawkins Radio Club. How many flashlights did each get?H

0/7 letters found

Clue 3

Percentages

A glowing sensor displays what percentage of the portal energy remains in the gym.

Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.

5% of 780 =B

25% of 96 =T

50% of 28 =H

60% of 45 =D

25% of 128 =S

50% of 62 =L

10% of 100 =G

10% of 260 =R

5% of 360 =V

50% of 10 =K

5% of 580 =C

10% of 450 =M

25% of 16 =I

40% of 90 =F

5% of 800 =O

20% of 210 =E

10% of 130 =A

0/17 letters found

Clue 4

Exponents

The radio signal power multiplies exponentially with each kilometer closer to the rift.

Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.

361

289

400

121

225

196

361

100

144

361

243

216

400

100

361

196

243

196

19^2 =A

5^2 =L

20^2 =U

14^2 =T

6^3 =O

2^2 =I

7^2 =E

2^5 =H

6^2 =D

11^2 =Y

12^2 =W

10^2 =N

15^2 =M

2^6 =R

2^3 =S

3^5 =F

17^2 =C

0/17 letters found

Clue 5

Missing addends — the last clue

You figure out how many more batteries are needed to fully power the containment trap.

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

38 + ___ = 42

24 + ___ = 30

34 + ___ = 39

33 + ___ = 36

23 + ___ = 30

11 + ___ = 19

34 + ___ = 43

27 + ___ = 28

34 + ___ = 36

25 + ___ = 35

3 + ___ = 15

Step 2 — cross out the sentence with each answer

1.The villain lit a portal spark, then raised a static shield.

2.The villain created a time echo, then raised a static shield.

3.The villain created a time echo, then froze with frost touch.

4.The villain blasted telekinesis, then blared a sound wave.

5.The villain wove a shadow cloak, then shot a laser glance.

6.The villain created a time echo, then blared a sound wave.

7.The villain blasted telekinesis, then shot a laser glance.

8.The villain cast a mind pulse, then shot a laser glance.

9.The villain blasted telekinesis, then caused a gravity flip.

10.The villain blasted telekinesis, then froze with frost touch.

11.The villain blasted telekinesis, then raised a static shield.

12.The villain cast a mind pulse, then raised a static shield.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Mystery of Echo Ridge

Culprit: Bob Newby (telekinesis · static shield · LEFT HANDED · CURLY MESH · BRIGHT FLASHLIGHT)

Clue 1 (Multiplication facts (1-12)): "THE VILLAIN DOES NOT USE FROST TOUCH"
12 × 11 = 132 (T) · 1 × 1 = 1 (I) · 12 × 9 = 108 (L) · 7 × 11 = 77 (V) · 1 × 2 = 2 (U) · 2 × 8 = 16 (S) · 10 × 10 = 100 (E) · 4 × 9 = 36 (R) · 8 × 8 = 64 (N) · 6 × 7 = 42 (H) · 3 × 11 = 33 (C) · 3 × 1 = 3 (D) · 12 × 12 = 144 (F) · 11 × 11 = 121 (O) · 7 × 8 = 56 (A)
Clue 2 (Multi-step word problems): "LEFT HANDED"
There were 242 waffles in all. 1 The Hawkins Radio Club used 12 waffles each. The other 5 The Hawkins Radio Club shared the rest equally. How many waffles did each of the other The Hawkins Radio Club get? = 46 (L) · AV Club Detective earned 6 walkie talkies in each of 2 rounds, plus 10 bonus walkie talkies. Then 6 walkie talkies were lost. How many walkie talkies are left? = 16 (T) · There were 95 twenty sided dice in all. 4 The Hawkins Radio Club used 14 twenty sided dice each. The other 3 The Hawkins Radio Club shared the rest equally. How many twenty sided dice did each of the other The Hawkins Radio Club get? = 13 (N) · There were 264 walkie talkies in all. 21 walkie talkies were set aside. The rest were shared equally among 3 The Hawkins Radio Club. How many walkie talkies did each get? = 81 (E) · There were 304 flashlights in all. 1 The Hawkins Radio Club used 28 flashlights each. The other 4 The Hawkins Radio Club shared the rest equally. How many flashlights did each of the other The Hawkins Radio Club get? = 69 (A) · There were 49 flashlights in all. 29 flashlights were set aside. The rest were shared equally among 2 The Hawkins Radio Club. How many flashlights did each get? = 10 (F) · AV Club Detective collected 2 flashlights in the morning and 262 flashlights in the afternoon, then split them equally among 4 The Hawkins Radio Club. How many flashlights did each get? = 66 (H)
Clue 3 (Percentages): "BRIGHT FLASHLIGHT BEAMS DROVE IT BACK"
5% of 780 = 39 (B) · 25% of 96 = 24 (T) · 50% of 28 = 14 (H) · 60% of 45 = 27 (D) · 25% of 128 = 32 (S) · 50% of 62 = 31 (L) · 10% of 100 = 10 (G) · 10% of 260 = 26 (R) · 5% of 360 = 18 (V) · 50% of 10 = 5 (K) · 5% of 580 = 29 (C) · 10% of 450 = 45 (M) · 25% of 16 = 4 (I) · 40% of 90 = 36 (F) · 5% of 800 = 40 (O) · 20% of 210 = 42 (E) · 10% of 130 = 13 (A)
Clue 4 (Exponents): "A CURLY MESH STRAND WAS FOUND NEAR THE RIFT"
19^2 = 361 (A) · 5^2 = 25 (L) · 20^2 = 400 (U) · 14^2 = 196 (T) · 6^3 = 216 (O) · 2^2 = 4 (I) · 7^2 = 49 (E) · 2^5 = 32 (H) · 6^2 = 36 (D) · 11^2 = 121 (Y) · 12^2 = 144 (W) · 10^2 = 100 (N) · 15^2 = 225 (M) · 2^6 = 64 (R) · 2^3 = 8 (S) · 3^5 = 243 (F) · 17^2 = 289 (C)
Clue 5 (Missing addends): surviving statement (box 11) → Bob Newby
38 + ___ = 42 = 4 · 24 + ___ = 30 = 6 · 34 + ___ = 39 = 5 · 33 + ___ = 36 = 3 · 23 + ___ = 30 = 7 · 11 + ___ = 19 = 8 · 34 + ___ = 43 = 9 · 27 + ___ = 28 = 1 · 34 + ___ = 36 = 2 · 25 + ___ = 35 = 10 · 3 + ___ = 15 = 12

About this mystery

Grade level: Grade 6 math
Math topics: Multiplication, Multi-step word problems, Percentages, Exponents, Missing addends
Reading level: grades 3-4
Theme: The Mystery of Echo Ridge — set in Echo Ridge Hawkins Hawkins Arcade and Research Lab
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

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