🤖 RobotsGrade 4Reading: grades 3-4MultiplicationRoundingAdditionSubtractionMissing addends

The Case of the Mischievous Mechanic

A sneaky robot snuck into the city lab and scrambled the blueprint vault! The Chief Inventor needs your help to decode the clues, track down the rogue robot, and save the workshop.

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 Tool	Secondary Gadget	Antenna Style	Head Wiring	System Weakness
Flux	Laser Torch	Glider Wings	Right Antenna Bent	Blue Cables	Water Spray
Bolt	Sonic Blaster	Glider Wings	Left Antenna Bent	Silver Filaments	Water Spray
Widget	Plasma Shield	Grappling Hook	Right Antenna Bent	Copper Wires	Water Spray
Pixel	Sonic Blaster	Hacking Deck	Left Antenna Bent	Silver Filaments	Water Spray
Sprocket	Plasma Shield	Glider Wings	Right Antenna Bent	Blue Cables	Water Spray
Turing	Magnet Arm	Hacking Deck	Left Antenna Bent	Silver Filaments	Foam Cannon
Nano	Laser Torch	Glider Wings	Right Antenna Bent	Blue Cables	Magnet Trap
Edison	Plasma Shield	EMP Pulser	Right Antenna Bent	Blue Cables	Foam Cannon
Byte	Plasma Shield	EMP Pulser	Left Antenna Bent	Silver Filaments	Water Spray
Circuit	Plasma Shield	Smoke Launcher	Right Antenna Bent	Silver Filaments	Foam Cannon
Micro	Laser Torch	Grappling Hook	Right Antenna Bent	Copper Wires	Water Spray
Tesla	Rocket Boots	Smoke Launcher	Left Antenna Bent	Copper Wires	Water Spray
Volt	Rocket Boots	EMP Pulser	Right Antenna Bent	Blue Cables	Foam Cannon
Turbo	Laser Torch	Glider Wings	Left Antenna Bent	Silver Filaments	Foam Cannon
Spark	Magnet Arm	EMP Pulser	Left Antenna Bent	Silver Filaments	Foam Cannon
Cog	Magnet Arm	Grappling Hook	Left Antenna Bent	Silver Filaments	Water Spray
Lovelace	Sonic Blaster	Grappling Hook	Left Antenna Bent	Silver Filaments	Water Spray
Vector	Sonic Blaster	Grappling Hook	Left Antenna Bent	Blue Cables	Foam Cannon
Gizmo	Plasma Shield	Hacking Deck	Right Antenna Bent	Silver Filaments	Water Spray
Asimov	Laser Torch	Hacking Deck	Right Antenna Bent	Copper Wires	Water Spray
Radar	Plasma Shield	Glider Wings	Right Antenna Bent	Silver Filaments	Foam Cannon

Clue 1

Multiplication facts (1-12)

You find a tray of battery cells arranged in equal rows. Counting them up by groups gives you 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.

144

110

5 × 7 =T

8 × 8 =M

3 × 1 =U

7 × 8 =P

2 × 10 =L

9 × 5 =I

7 × 12 =R

12 × 12 =V

1 × 1 =N

6 × 3 =S

3 × 5 =O

10 × 6 =A

9 × 9 =E

6 × 11 =H

10 × 11 =D

0/15 letters found

Clue 2

Rounding

The security console rounds all voltage readings to the nearest hundred. The display reveals a hidden hint!

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

130

230

3700

2300

7000

170

2300

130

3700

2300

3700

130

1100

130

370

3700

9000

3700

290

130

3000

2900

130

Round 128 to the nearest tenA

Round 368 to the nearest tenS

Round 170 to the nearest tenF

Round 8,716 to the nearest thousandO

Round 3,046 to the nearest thousandM

Round 3,711 to the nearest hundredN

Round 233 to the nearest tenB

Round 1,097 to the nearest hundredW

Round 70 to the nearest tenE

Round 2,908 to the nearest hundredR

Round 2,292 to the nearest hundredT

Round 287 to the nearest tenC

Round 7,301 to the nearest thousandL

0/13 letters found

Clue 3

Addition

By adding up all the spare gears found near the workbench, you piece together another 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.

4660

2347

4181

6823

4561

7754

6697

4561

5247

3277

7754

4181

7701

3277

3050

3792

2547

6079

6697

4660

4181

3050

7701

4685

3050

6697

7524

2028 + 2632 =T

1160 + 1890 =R

1640 + 907 =M

3105 + 3592 =A

1404 + 943 =H

4621 + 3133 =L

4150 + 2673 =V

1458 + 3227 =P

1981 + 3266 =N

2097 + 1695 =O

1336 + 1941 =F

1831 + 4248 =W

4262 + 3262 =Y

2124 + 2437 =I

2537 + 1644 =E

2920 + 4781 =S

0/16 letters found

Clue 4

Subtraction

You calculate the energy remaining after subtracting used power units from the main battery grid.

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

6265

7385

3728

2660

8793

7653

1442

7385

3728

3676

6367

8793

1924

8080

6265

8446

8793

7653

8793

1442

3902

6232

1924

6471

3902

1924

8080

4228

8793

1442

3728

3902

7653

6503 - 238 =S

6448 - 2772 =A

13310 - 4864 =W

11165 - 3780 =I

6022 - 4098 =N

11217 - 3137 =T

7160 - 4500 =V

7370 - 3468 =O

6616 - 2888 =L

8449 - 4221 =H

11473 - 3820 =R

2781 - 1339 =F

10162 - 3691 =D

10282 - 1489 =E

8079 - 1847 =U

11097 - 4730 =M

0/16 letters found

Clue 5

Missing addends — the last clue

The terminal needs a missing power total to unlock the file. Find the missing amount to get your 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

22 + ___ = 32

12 + ___ = 19

11 + ___ = 17

18 + ___ = 23

33 + ___ = 36

31 + ___ = 40

27 + ___ = 29

35 + ___ = 36

5 + ___ = 17

6 + ___ = 14

22 + ___ = 26

Step 2 — cross out the sentence with each answer

1.The villain swung the magnet arm, then triggered an emp pulser.

2.The villain fired the laser torch, then unfolded glider wings.

3.The villain activated rocket boots, then launched a smoke bomb.

4.The villain fired the laser torch, then launched a smoke bomb.

5.The villain fired the laser torch, then fired a grappling hook.

6.The villain blasted the sonic cannon, then fired a grappling hook.

7.The villain swung the magnet arm, then fired a grappling hook.

8.The villain blasted the sonic cannon, then launched a smoke bomb.

9.The villain swung the magnet arm, then launched a smoke bomb.

10.The villain blasted the sonic cannon, then unfolded glider wings.

11.The villain blasted the sonic cannon, then plugged in a hacking deck.

12.The villain activated rocket boots, then triggered an emp pulser.

Solve it

Name the culprit

Choose the one suspect left standing.

Answer Key — The Case of the Mischievous Mechanic

Culprit: Pixel (Sonic Blaster · Hacking Deck · Left Antenna Bent · Silver Filaments · Water Spray)

Clue 1 (Multiplication facts (1-12)): "THE VILLAIN DOES NOT USE AN EMP PULSER"
5 × 7 = 35 (T) · 8 × 8 = 64 (M) · 3 × 1 = 3 (U) · 7 × 8 = 56 (P) · 2 × 10 = 20 (L) · 9 × 5 = 45 (I) · 7 × 12 = 84 (R) · 12 × 12 = 144 (V) · 1 × 1 = 1 (N) · 6 × 3 = 18 (S) · 3 × 5 = 15 (O) · 10 × 6 = 60 (A) · 9 × 9 = 81 (E) · 6 × 11 = 66 (H) · 10 × 11 = 110 (D)
Clue 2 (Rounding): "A BENT LEFT ANTENNA WAS SEEN ON CAMERA"
Round 128 to the nearest ten = 130 (A) · Round 368 to the nearest ten = 370 (S) · Round 170 to the nearest ten = 170 (F) · Round 8,716 to the nearest thousand = 9000 (O) · Round 3,046 to the nearest thousand = 3000 (M) · Round 3,711 to the nearest hundred = 3700 (N) · Round 233 to the nearest ten = 230 (B) · Round 1,097 to the nearest hundred = 1100 (W) · Round 70 to the nearest ten = 70 (E) · Round 2,908 to the nearest hundred = 2900 (R) · Round 2,292 to the nearest hundred = 2300 (T) · Round 287 to the nearest ten = 290 (C) · Round 7,301 to the nearest thousand = 7000 (L)
Clue 3 (Addition): "THE VILLAIN FLEES FROM WATER SPRAY"
2028 + 2632 = 4660 (T) · 1160 + 1890 = 3050 (R) · 1640 + 907 = 2547 (M) · 3105 + 3592 = 6697 (A) · 1404 + 943 = 2347 (H) · 4621 + 3133 = 7754 (L) · 4150 + 2673 = 6823 (V) · 1458 + 3227 = 4685 (P) · 1981 + 3266 = 5247 (N) · 2097 + 1695 = 3792 (O) · 1336 + 1941 = 3277 (F) · 1831 + 4248 = 6079 (W) · 4262 + 3262 = 7524 (Y) · 2124 + 2437 = 4561 (I) · 2537 + 1644 = 4181 (E) · 2920 + 4781 = 7701 (S)
Clue 4 (Subtraction): "SILVER FILAMENTS WERE FOUND ON THE FLOOR"
6503 - 238 = 6265 (S) · 6448 - 2772 = 3676 (A) · 13310 - 4864 = 8446 (W) · 11165 - 3780 = 7385 (I) · 6022 - 4098 = 1924 (N) · 11217 - 3137 = 8080 (T) · 7160 - 4500 = 2660 (V) · 7370 - 3468 = 3902 (O) · 6616 - 2888 = 3728 (L) · 8449 - 4221 = 4228 (H) · 11473 - 3820 = 7653 (R) · 2781 - 1339 = 1442 (F) · 10162 - 3691 = 6471 (D) · 10282 - 1489 = 8793 (E) · 8079 - 1847 = 6232 (U) · 11097 - 4730 = 6367 (M)
Clue 5 (Missing addends): surviving statement (box 11) → Pixel
22 + ___ = 32 = 10 · 12 + ___ = 19 = 7 · 11 + ___ = 17 = 6 · 18 + ___ = 23 = 5 · 33 + ___ = 36 = 3 · 31 + ___ = 40 = 9 · 27 + ___ = 29 = 2 · 35 + ___ = 36 = 1 · 5 + ___ = 17 = 12 · 6 + ___ = 14 = 8 · 22 + ___ = 26 = 4

About this mystery

Grade level: Grade 4 math
Math topics: Multiplication, Rounding, Addition, Subtraction, Missing addends
Reading level: grades 3-4
Theme: The Case of the Mischievous Mechanic — set in Gearshift City Robotics Lab
Format: Interactive online & printable worksheet with answer key
Solution: One unique, verified culprit among 21 suspects

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