🦕 DinosaursGrade 3Reading: grades 3-4MultiplicationAdditionSubtractionPlace valueDivision

The Great Dino Dig Mystery

A rare T-rex skull has vanished from Fossil Ridge! The Chief Paleontologist needs your detective skills to track down the thief and recover the fossil.

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	Dig Tool	Tracking Gear	Watch Wrist	Headgear	Weakness
Chisel Charlie	Laser Scanner	Thermal Sensor	Right Wrist Watch	Safari Fedora	Sticky Resin
Sammy Fossil	Laser Scanner	GPS Beacon	Right Wrist Watch	Raptor Beanie	Sticky Resin
Dino Dan	Steel Pickaxe	Radio Tracker	Right Wrist Watch	Rex Cap	Loud Whistle
Archie Armor	Sonic Chisel	Night Goggles	Right Wrist Watch	Raptor Beanie	Bright Flash
Bone Hunter Bob	Dust Blower	Radio Tracker	Left Wrist Watch	Rex Cap	Loud Whistle
Canyon Cole	Dust Blower	Drone Remote	Left Wrist Watch	Raptor Beanie	Loud Whistle
Tara Talon	Rock Hammer	GPS Beacon	Left Wrist Watch	Raptor Beanie	Bright Flash
Digging Daisy	Dust Blower	Thermal Sensor	Right Wrist Watch	Rex Cap	Sticky Resin
Dr Mary Anning	Dust Blower	Drone Remote	Left Wrist Watch	Raptor Beanie	Sticky Resin
Fossil Frank	Rock Hammer	Thermal Sensor	Right Wrist Watch	Safari Fedora	Sticky Resin
Maya Mesozoic	Steel Pickaxe	Radio Tracker	Right Wrist Watch	Rex Cap	Bright Flash
Ranger Rex	Laser Scanner	Thermal Sensor	Right Wrist Watch	Rex Cap	Sticky Resin
Hugo Horn	Laser Scanner	GPS Beacon	Right Wrist Watch	Rex Cap	Sticky Resin
Brite Bones	Rock Hammer	Radio Tracker	Right Wrist Watch	Safari Fedora	Bright Flash
Gabi Ground	Steel Pickaxe	GPS Beacon	Right Wrist Watch	Rex Cap	Sticky Resin
Tracker Trixie	Laser Scanner	Night Goggles	Right Wrist Watch	Safari Fedora	Bright Flash
Sully Stratum	Laser Scanner	Radio Tracker	Right Wrist Watch	Safari Fedora	Loud Whistle
Prof Barnum Brown	Sonic Chisel	Night Goggles	Left Wrist Watch	Safari Fedora	Bright Flash
Quinn Quarry	Laser Scanner	Radio Tracker	Left Wrist Watch	Rex Cap	Sticky Resin
Zack Zircon	Laser Scanner	Drone Remote	Right Wrist Watch	Rex Cap	Sticky Resin
Explorer Emma	Steel Pickaxe	GPS Beacon	Left Wrist Watch	Rex Cap	Sticky Resin

Clue 1

Multiplication facts (1-12)

You count the crates of fossil brushes packed in identical rows to decrypt the first log.

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

144

132

7 × 7 =T

5 × 3 =M

9 × 9 =D

6 × 1 =L

8 × 8 =O

12 × 12 =I

8 × 12 =A

11 × 4 =N

11 × 2 =E

9 × 3 =R

4 × 2 =V

12 × 11 =S

12 × 7 =U

10 × 2 =H

0/14 letters found

Clue 2

Addition

Adding up the total dinosaur teeth collected today unlocks another encoded transmission.

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

312

541

950

628

665

237

930

312

846

950

214

496

628

214

846

214

312

665

541

237

455

312

541

950

496

660

616

541

312

846

496

660

628

312

105 + 207 =T

318 + 632 =E

265 + 363 =S

88 + 149 =O

174 + 367 =H

231 + 265 =R

97 + 117 =A

429 + 187 =G

333 + 597 =U

587 + 259 =W

229 + 436 =C

387 + 273 =I

153 + 302 =N

0/13 letters found

Clue 3

Subtraction

Subtracting the damaged rock samples from the total pile reveals the next scrambled lead.

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

278

760

805

465

411

439

597

411

845

150

597

747

278

644

140

805

463

730

659

747

278

411

116

454

659

423

805

747

411

845

292 - 14 =T

516 - 376 =P

357 - 207 =W

1084 - 324 =H

1092 - 362 =B

535 - 96 =L

1011 - 264 =S

1196 - 351 =N

581 - 170 =I

872 - 275 =A

1019 - 214 =E

826 - 182 =O

670 - 11 =Y

600 - 146 =K

603 - 140 =D

412 - 296 =C

611 - 146 =V

617 - 194 =R

0/18 letters found

Clue 4

Place value

Checking the place value digits on the camp radio frequency unscrambles the hidden tape.

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

900

3000

600

900

500

900

8000

700

6000

5000

300

400

2000

900

5000

400

2000

200

8000

5000

What is the value of the 9 in 8,900?A

What is the value of the 6 in 644?X

What is the value of the 9 in 796?W

What is the value of the 6 in 86,031?F

What is the value of the 2 in 7,250?G

What is the value of the 7 in 9,474?I

What is the value of the 7 in 4,718?L

What is the value of the 8 in 8,621?S

What is the value of the 6 in 962?C

What is the value of the 5 in 5,378?T

What is the value of the 2 in 9,826?E

What is the value of the 4 in 408?H

What is the value of the 2 in 32,460?D

What is the value of the 5 in 1,599?P

What is the value of the 3 in 43,790?R

What is the value of the 3 in 1,319?B

What is the value of the 4 in 6,248?N

0/17 letters found

Clue 5

Division facts (1-12) — the last clue

Splitting the supply rations equally among the research teams decodes the 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

6 ÷ 1 = ?

16 ÷ 4 = ?

110 ÷ 10 = ?

9 ÷ 9 = ?

108 ÷ 9 = ?

63 ÷ 7 = ?

10 ÷ 2 = ?

21 ÷ 3 = ?

6 ÷ 2 = ?

22 ÷ 11 = ?

48 ÷ 6 = ?

Step 2 — cross out the sentence with each answer

1.The villain uses a sonic chisel to dig, then checks the night goggles.

2.The villain clears dust with a blower, then tunes the radio tracker.

3.The villain uses a sonic chisel to dig, then tunes the radio tracker.

4.The villain clears dust with a blower, then reads the thermal sensor.

5.The villain swings a rock hammer, then tunes the radio tracker.

6.The villain swings a steel pickaxe, then tracks the gps beacon.

7.The villain scans bones with a laser, then tunes the radio tracker.

8.The villain clears dust with a blower, then checks the night goggles.

9.The villain swings a steel pickaxe, then checks the night goggles.

10.The villain scans bones with a laser, then reads the thermal sensor.

11.The villain scans bones with a laser, then tracks the gps beacon.

12.The villain swings a rock hammer, then reads the thermal sensor.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Great Dino Dig Mystery

Culprit: Ranger Rex (Laser Scanner · Thermal Sensor · Right Wrist Watch · Rex Cap · Sticky Resin)

Clue 1 (Multiplication facts (1-12)): "THE VILLAIN DOES NOT USE A DRONE REMOTE"
7 × 7 = 49 (T) · 5 × 3 = 15 (M) · 9 × 9 = 81 (D) · 6 × 1 = 6 (L) · 8 × 8 = 64 (O) · 12 × 12 = 144 (I) · 8 × 12 = 96 (A) · 11 × 4 = 44 (N) · 11 × 2 = 22 (E) · 9 × 3 = 27 (R) · 4 × 2 = 8 (V) · 12 × 11 = 132 (S) · 12 × 7 = 84 (U) · 10 × 2 = 20 (H)
Clue 2 (Addition): "THE SCOUT WEARS A WATCH ON THE RIGHT WRIST"
105 + 207 = 312 (T) · 318 + 632 = 950 (E) · 265 + 363 = 628 (S) · 88 + 149 = 237 (O) · 174 + 367 = 541 (H) · 231 + 265 = 496 (R) · 97 + 117 = 214 (A) · 429 + 187 = 616 (G) · 333 + 597 = 930 (U) · 587 + 259 = 846 (W) · 229 + 436 = 665 (C) · 387 + 273 = 660 (I) · 153 + 302 = 455 (N)
Clue 3 (Subtraction): "THE VILLAIN WAS STOPPED BY STICKY RESIN"
292 - 14 = 278 (T) · 516 - 376 = 140 (P) · 357 - 207 = 150 (W) · 1084 - 324 = 760 (H) · 1092 - 362 = 730 (B) · 535 - 96 = 439 (L) · 1011 - 264 = 747 (S) · 1196 - 351 = 845 (N) · 581 - 170 = 411 (I) · 872 - 275 = 597 (A) · 1019 - 214 = 805 (E) · 826 - 182 = 644 (O) · 670 - 11 = 659 (Y) · 600 - 146 = 454 (K) · 603 - 140 = 463 (D) · 412 - 296 = 116 (C) · 611 - 146 = 465 (V) · 617 - 194 = 423 (R)
Clue 4 (Place value): "A REX CAP WAS LEFT BEHIND AT THE DIG SITE"
What is the value of the 9 in 8,900? = 900 (A) · What is the value of the 6 in 644? = 600 (X) · What is the value of the 9 in 796? = 90 (W) · What is the value of the 6 in 86,031? = 6000 (F) · What is the value of the 2 in 7,250? = 200 (G) · What is the value of the 7 in 9,474? = 70 (I) · What is the value of the 7 in 4,718? = 700 (L) · What is the value of the 8 in 8,621? = 8000 (S) · What is the value of the 6 in 962? = 60 (C) · What is the value of the 5 in 5,378? = 5000 (T) · What is the value of the 2 in 9,826? = 20 (E) · What is the value of the 4 in 408? = 400 (H) · What is the value of the 2 in 32,460? = 2000 (D) · What is the value of the 5 in 1,599? = 500 (P) · What is the value of the 3 in 43,790? = 3000 (R) · What is the value of the 3 in 1,319? = 300 (B) · What is the value of the 4 in 6,248? = 40 (N)
Clue 5 (Division facts (1-12)): surviving statement (box 10) → Ranger Rex
6 ÷ 1 = 6 · 16 ÷ 4 = 4 · 110 ÷ 10 = 11 · 9 ÷ 9 = 1 · 108 ÷ 9 = 12 · 63 ÷ 7 = 9 · 10 ÷ 2 = 5 · 21 ÷ 3 = 7 · 6 ÷ 2 = 3 · 22 ÷ 11 = 2 · 48 ÷ 6 = 8

About this mystery

Grade level: Grade 3 math
Math topics: Multiplication, Addition, Subtraction, Place value, Division
Reading level: grades 3-4
Theme: The Great Dino Dig Mystery — set in Fossil Ridge Dig Site
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

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