Grade 4Reading: grades 3-4RoundingAdditionSubtractionMultiplicationDivision

The Case of the Missing Dino Egg

Something is wrong in Thunder Valley. The shiny Golden Dino Egg vanished from its nest while everyone slept, and big tracks lead off into the ferns. You are the valley's best young detective, so the herd is counting on you to sniff out the sneaky Egg Snatcher.

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	Dino Kind	Special Move	Boy or Girl	Scale Color	Weakness
Dash	Triceratops	mud tunneling	boy dino	green scales	scared of thunder
Pebbles	Velociraptor	booming roar	girl dino	brown scales	loves shiny rocks
Stompy	T Rex	mud tunneling	boy dino	green scales	loves shiny rocks
Rocky	Pterodactyl	booming roar	boy dino	green scales	scared of thunder
Spike	Triceratops	mud tunneling	girl dino	brown scales	ticklish feet
Swoop	Pterodactyl	cliff climbing	girl dino	green scales	scared of thunder
Petrie	T Rex	booming roar	girl dino	brown scales	loves shiny rocks
Ducky	T Rex	mud tunneling	boy dino	blue scales	ticklish feet
Trixie	Stegosaurus	river splashing	boy dino	green scales	scared of thunder
Crunch	Pterodactyl	river splashing	boy dino	green scales	scared of thunder
Ferny	T Rex	booming roar	boy dino	brown scales	scared of thunder
Dot	Stegosaurus	booming roar	boy dino	green scales	loves shiny rocks
Cera	T Rex	booming roar	boy dino	blue scales	scared of thunder
Littlefoot	T Rex	cliff climbing	boy dino	green scales	scared of thunder
Razor	Pterodactyl	fern hiding	girl dino	brown scales	loves shiny rocks
Bumpy	Pterodactyl	booming roar	girl dino	green scales	ticklish feet
Dizzy	Pterodactyl	river splashing	girl dino	brown scales	ticklish feet
Tilly	Pterodactyl	cliff climbing	girl dino	blue scales	ticklish feet
Bronto	Pterodactyl	mud tunneling	girl dino	green scales	ticklish feet
Mossy	Pterodactyl	mud tunneling	boy dino	brown scales	loves shiny rocks
Nessa	T Rex	booming roar	girl dino	green scales	loves shiny rocks

Clue 1

Rounding

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

2000

4700000

2800

140000

31000

14000

140000

3000

470

14000

3000

300000

2000

20000

3000

4700000

31000

20000

3000

5000

4700000

700

280

20000

5000

Round 1,984 to the nearest thousandT

Round 28 to the nearest tenH

Round 4,669,005 to the nearest hundred thousandE

Round 2,788 to the nearest hundredV

Round 139,570 to the nearest ten thousandI

Round 31,042 to the nearest thousandL

Round 13,857 to the nearest thousandA

Round 3,136 to the nearest thousandN

Round 474 to the nearest tenC

Round 307,866 to the nearest hundred thousandO

Round 18,962 to the nearest ten thousandU

Round 4,602 to the nearest thousandD

Round 696 to the nearest hundredR

Round 280 to the nearest tenM

0/14 letters found

Clue 2

Addition

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

4507

8261

7929

4618

9656

7439

3373

4507

8261

4507

9397

3929

6240

7493

7929

9656

3929

7886

6631

9656

3929

3090

2613 + 1894 =A

2898 + 5363 =W

4696 + 3233 =I

3100 + 1518 =T

3272 + 6384 =N

3186 + 4253 =E

1781 + 1592 =S

6178 + 3219 =B

2383 + 1546 =O

3697 + 2543 =Y

2251 + 5242 =D

3068 + 4818 =R

4335 + 2296 =U

2039 + 1051 =F

0/14 letters found

Clue 3

Subtraction

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

8076

8426

1705

1831

2048

1723

7553

1831

8602

2048

2526

7049

8989

8426

8076

1087

4432

8989

8076

7049

2526

2048

2157

1723

1705

2152

9333 - 1257 =A

12346 - 3920 =L

2149 - 444 =O

2763 - 932 =U

6007 - 3959 =D

3355 - 1632 =T

11501 - 3948 =H

9190 - 588 =N

3066 - 540 =E

8340 - 1291 =R

10528 - 1539 =C

1224 - 137 =P

9082 - 4650 =S

4216 - 2059 =I

5508 - 3356 =F

0/15 letters found

Clue 4

Multiplication facts (1–12)

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

120

3 × 7 =A

6 × 4 =G

12 × 10 =R

7 × 2 =E

9 × 10 =N

11 × 5 =S

11 × 1 =C

11 × 2 =L

8 × 8 =Y

9 × 1 =B

6 × 10 =T

3 × 9 =H

0/12 letters found

Clue 5

Division facts (1–12) — the last 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

63 ÷ 9 = ?

30 ÷ 10 = ?

48 ÷ 12 = ?

42 ÷ 7 = ?

27 ÷ 3 = ?

66 ÷ 6 = ?

32 ÷ 4 = ?

55 ÷ 11 = ?

8 ÷ 8 = ?

132 ÷ 11 = ?

10 ÷ 5 = ?

Step 2 — cross out the sentence with each answer

1.The villain charges with three sharp horns, then climbs up the rocky cliffs.

2.The villain darts in on quick claws, then hides low in the tall ferns.

3.The villain stomps in with huge jaws, then climbs up the rocky cliffs.

4.The villain swoops down from the sky, then lets out a booming roar.

5.The villain stomps in with huge jaws, then splashes across the wide river.

6.The villain swoops down from the sky, then hides low in the tall ferns.

7.The villain swoops down from the sky, then splashes across the wide river.

8.The villain stomps in with huge jaws, then lets out a booming roar.

9.The villain charges with three sharp horns, then lets out a booming roar.

10.The villain swings its spiky tail, then splashes across the wide river.

11.The villain darts in on quick claws, then tunnels under the soft mud.

12.The villain swings its spiky tail, then tunnels under the soft mud.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Case of the Missing Dino Egg

Culprit: Trixie (Stegosaurus · river splashing · boy dino · green scales · scared of thunder)

Clue 1 (Rounding): "THE VILLAIN CANNOT TUNNEL UNDER MUD"
Round 1,984 to the nearest thousand = 2000 (T) · Round 28 to the nearest ten = 30 (H) · Round 4,669,005 to the nearest hundred thousand = 4700000 (E) · Round 2,788 to the nearest hundred = 2800 (V) · Round 139,570 to the nearest ten thousand = 140000 (I) · Round 31,042 to the nearest thousand = 31000 (L) · Round 13,857 to the nearest thousand = 14000 (A) · Round 3,136 to the nearest thousand = 3000 (N) · Round 474 to the nearest ten = 470 (C) · Round 307,866 to the nearest hundred thousand = 300000 (O) · Round 18,962 to the nearest ten thousand = 20000 (U) · Round 4,602 to the nearest thousand = 5000 (D) · Round 696 to the nearest hundred = 700 (R) · Round 280 to the nearest ten = 280 (M)
Clue 2 (Addition): "A WITNESS SAW A BOY DINO RUN OFF"
2613 + 1894 = 4507 (A) · 2898 + 5363 = 8261 (W) · 4696 + 3233 = 7929 (I) · 3100 + 1518 = 4618 (T) · 3272 + 6384 = 9656 (N) · 3186 + 4253 = 7439 (E) · 1781 + 1592 = 3373 (S) · 6178 + 3219 = 9397 (B) · 2383 + 1546 = 3929 (O) · 3697 + 2543 = 6240 (Y) · 2251 + 5242 = 7493 (D) · 3068 + 4818 = 7886 (R) · 4335 + 2296 = 6631 (U) · 2039 + 1051 = 3090 (F)
Clue 3 (Subtraction): "A LOUD THUNDER CLAP SCARED IT OFF"
9333 - 1257 = 8076 (A) · 12346 - 3920 = 8426 (L) · 2149 - 444 = 1705 (O) · 2763 - 932 = 1831 (U) · 6007 - 3959 = 2048 (D) · 3355 - 1632 = 1723 (T) · 11501 - 3948 = 7553 (H) · 9190 - 588 = 8602 (N) · 3066 - 540 = 2526 (E) · 8340 - 1291 = 7049 (R) · 10528 - 1539 = 8989 (C) · 1224 - 137 = 1087 (P) · 9082 - 4650 = 4432 (S) · 4216 - 2059 = 2157 (I) · 5508 - 3356 = 2152 (F)
Clue 4 (Multiplication facts (1–12)): "A GREEN SCALE LAY BY THE NEST"
3 × 7 = 21 (A) · 6 × 4 = 24 (G) · 12 × 10 = 120 (R) · 7 × 2 = 14 (E) · 9 × 10 = 90 (N) · 11 × 5 = 55 (S) · 11 × 1 = 11 (C) · 11 × 2 = 22 (L) · 8 × 8 = 64 (Y) · 9 × 1 = 9 (B) · 6 × 10 = 60 (T) · 3 × 9 = 27 (H)
Clue 5 (Division facts (1–12)): surviving statement (box 10) → Trixie
63 ÷ 9 = 7 · 30 ÷ 10 = 3 · 48 ÷ 12 = 4 · 42 ÷ 7 = 6 · 27 ÷ 3 = 9 · 66 ÷ 6 = 11 · 32 ÷ 4 = 8 · 55 ÷ 11 = 5 · 8 ÷ 8 = 1 · 132 ÷ 11 = 12 · 10 ÷ 5 = 2

About this mystery

Grade level: Grade 4 math
Math topics: Rounding, Addition, Subtraction, Multiplication, Division
Reading level: grades 3-4
Theme: The Case of the Missing Dino Egg — set in Thunder Valley
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects