🤖 RobotsGrade 4Reading: grades 3-4Fractions of a numberMultiplicationMulti-step word problemsRounding
The Great Mech Workshop Mystery
Someone broke into the Gearshift City Robotics Lab and scrambled the master blueprint for the ultimate helper robot! As lead detective of the Robotics Squad, you must examine the evidence, solve the clues, and catch the rogue bot before the grand unveiling.
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 System | Secondary Module | Sensor Light | Head Gear | System Vulnerability |
|---|---|---|---|---|---|
| Sparky | Turbo Jump | Oil Sprayer | Flashing Red LED | Copper Crown | Strong Magnets |
| Byte | Turbo Jump | Solar Panel | Flashing Blue LED | Neon Wires | Strong Magnets |
| Circuit | Laser Beam | Rocket Boots | Flashing Blue LED | Neon Wires | Giant Sponge |
| Vector | Shield Guard | Solar Panel | Flashing Red LED | Neon Wires | Giant Sponge |
| Sprocket | Sonic Blast | Smoke Screen | Flashing Red LED | Copper Crown | Giant Sponge |
| Voltage | Laser Beam | Rocket Boots | Flashing Red LED | Neon Wires | Strong Magnets |
| Transistor | Sonic Blast | Oil Sprayer | Flashing Red LED | Steel Spikes | Strong Magnets |
| RustE | Repair Arm | Hacking Chip | Flashing Blue LED | Copper Crown | Strong Magnets |
| Matrix | Sonic Blast | Rocket Boots | Flashing Red LED | Copper Crown | Strong Magnets |
| Bolt | Sonic Blast | Solar Panel | Flashing Red LED | Neon Wires | Giant Sponge |
| Micro | Sonic Blast | Smoke Screen | Flashing Blue LED | Neon Wires | Giant Sponge |
| Turbo | Repair Arm | Hacking Chip | Flashing Red LED | Neon Wires | Giant Sponge |
| Widget | Sonic Blast | Rocket Boots | Flashing Red LED | Neon Wires | Strong Magnets |
| Cogsworth | Repair Arm | Smoke Screen | Flashing Blue LED | Steel Spikes | Rusty Water |
| Amp | Laser Beam | Hacking Chip | Flashing Red LED | Copper Crown | Strong Magnets |
| Pixel | Turbo Jump | Rocket Boots | Flashing Red LED | Neon Wires | Giant Sponge |
| Dynamo | Turbo Jump | Smoke Screen | Flashing Blue LED | Steel Spikes | Rusty Water |
| Capacitor | Sonic Blast | Smoke Screen | Flashing Red LED | Neon Wires | Giant Sponge |
| Gearhead | Shield Guard | Oil Sprayer | Flashing Blue LED | Steel Spikes | Strong Magnets |
| Glitch | Laser Beam | Smoke Screen | Flashing Blue LED | Neon Wires | Giant Sponge |
| Gizmo | Turbo Jump | Oil Sprayer | Flashing Blue LED | Steel Spikes | Strong Magnets |
Clue 1
Fractions of a number
We scanned the lab crates to find out which missing parts were taken.
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
27
17
22
10
19
22
16
28
18
2
34
T
27
3
34
22
10
19
34
T
27
40
10
22
16
17
16
13
28
36
19
20
13
17
36
38
6/10 of 45 =T
2/10 of 90 =Y
2/8 of 64 =A
4/10 of 85 =O
1/5 of 65 =C
4/8 of 4 =B
1/3 of 9 =D
4/5 of 25 =G
2/6 of 66 =E
2/5 of 95 =P
5/10 of 72 =I
2/4 of 56 =K
3/6 of 80 =U
1/5 of 95 =N
1/5 of 85 =H
2/5 of 25 =S
0/16 letters found
Clue 2
Multiplication facts (1-12)
Our scanner counted the power cells organized in even rows across the storage 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.
A
14
70
80
110
66
108
24
24
24
A
14
70
A
14
21
44
A
14
24
72
80
66
96
54
108
90
44
108
90
121
66
110
121
9
7 × 2 =A
6 × 11 =N
12 × 9 =E
11 × 11 =O
9 × 10 =D
8 × 12 =G
11 × 4 =L
10 × 11 =T
3 × 3 =P
4 × 6 =S
10 × 8 =I
12 × 6 =H
9 × 6 =R
3 × 7 =F
7 × 10 =W
0/15 letters found
Clue 3
Multi-step word problems
We tracked the battery usage across three charging stations to calculate total energy left.
Solve each problem to learn its letter, then write the letters in the boxes to fill in the missing word.
Someonescaredthevillainoffwith .
G
9
59
7
87
60
74
78
O
87
G
9
E
Head engineer collected 15 copper coils in the morning and 3 copper coils in the afternoon, then split them equally among 2 Robotics Squad. How many copper coils did each get?G
Head engineer filled 6 boxes with 8 microchips each, then found 26 more microchips. How many microchips are there in all?S
Head engineer collected 25 copper coils in the morning and 3 copper coils in the afternoon, then split them equally among 4 Robotics Squad. How many copper coils did each get?A
Head engineer collected 18 copper coils in the morning and 330 copper coils in the afternoon, then split them equally among 4 Robotics Squad. How many copper coils did each get?N
There were 413 gear wheels in all. 23 gear wheels were set aside. The rest were shared equally among 5 Robotics Squad. How many gear wheels did each get?P
Head engineer filled 3 boxes with 9 battery packs each, then found 33 more battery packs. How many battery packs are there in all?T
Head engineer earned 2 battery packs in each of 4 rounds, plus 55 bonus battery packs. Then 4 battery packs were lost. How many battery packs are left?I
0/7 letters found
Clue 4
Rounding
The digital radar display rounded the distance to the nearest ten 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.
W
1100
290
2000
110
2300
700
4300
700
290
110
700
W
1100
1700
170
290
50
70
290
2000
20
3000
20
20
2900
290
90
170
1700
900
290
50
90
290
700
290
Round 1,087 to the nearest hundredW
Round 18 to the nearest tenT
Round 2,911 to the nearest hundredH
Round 69 to the nearest tenL
Round 289 to the nearest tenE
Round 1,692 to the nearest hundredI
Round 660 to the nearest hundredN
Round 2,315 to the nearest hundredU
Round 2,254 to the nearest thousandF
Round 110 to the nearest tenO
Round 905 to the nearest hundredM
Round 50 to the nearest tenS
Round 90 to the nearest tenC
Round 171 to the nearest tenR
Round 4,297 to the nearest hundredD
Round 2,747 to the nearest thousandA
0/16 letters found
Clue 5
Fractions of a number — the last clue
We analyzed a fraction of the digital log entries left on the central mainframe.
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
1/10 of 80 = ?
1/5 of 55 = ?
1/2 of 24 = ?
4/10 of 15 = ?
5/10 of 4 = ?
6/10 of 5 = ?
2/6 of 3 = ?
1/2 of 20 = ?
1/4 of 28 = ?
6/8 of 12 = ?
2/6 of 15 = ?
Step 2 — cross out the sentence with each answer
1.The villain used turbo jump, then installed a hacking chip.
2.The villain activated repair arm, then released a smoke screen.
3.The villain blasted sonic waves, then boosted with rocket boots.
4.The villain blasted sonic waves, then charged solar panels.
5.The villain fired a laser beam, then released a smoke screen.
6.The villain blasted sonic waves, then installed a hacking chip.
7.The villain used turbo jump, then charged solar panels.
8.The villain raised shield guard, then charged solar panels.
9.The villain activated repair arm, then boosted with rocket boots.
10.The villain activated repair arm, then sprayed slippery oil.
11.The villain used turbo jump, then boosted with rocket boots.
12.The villain blasted sonic waves, then released a smoke screen.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Great Mech Workshop Mystery
Culprit: Bolt (Sonic Blast · Solar Panel · Flashing Red LED · Neon Wires · Giant Sponge)
- Clue 1 (Fractions of a number): "THE SNEAKY BOT DOES NOT USE A HACKING CHIP"6/10 of 45 = 27 (T) · 2/10 of 90 = 18 (Y) · 2/8 of 64 = 16 (A) · 4/10 of 85 = 34 (O) · 1/5 of 65 = 13 (C) · 4/8 of 4 = 2 (B) · 1/3 of 9 = 3 (D) · 4/5 of 25 = 20 (G) · 2/6 of 66 = 22 (E) · 2/5 of 95 = 38 (P) · 5/10 of 72 = 36 (I) · 2/4 of 56 = 28 (K) · 3/6 of 80 = 40 (U) · 1/5 of 95 = 19 (N) · 1/5 of 85 = 17 (H) · 2/5 of 25 = 10 (S)
- Clue 2 (Multiplication facts (1-12)): "A WITNESS SAW A FLASHING RED LED ON TOP"7 × 2 = 14 (A) · 6 × 11 = 66 (N) · 12 × 9 = 108 (E) · 11 × 11 = 121 (O) · 9 × 10 = 90 (D) · 8 × 12 = 96 (G) · 11 × 4 = 44 (L) · 10 × 11 = 110 (T) · 3 × 3 = 9 (P) · 4 × 6 = 24 (S) · 10 × 8 = 80 (I) · 12 × 6 = 72 (H) · 9 × 6 = 54 (R) · 3 × 7 = 21 (F) · 7 × 10 = 70 (W)
- Clue 3 (Multi-step word problems): "GIANT SPONGE"Head engineer collected 15 copper coils in the morning and 3 copper coils in the afternoon, then split them equally among 2 Robotics Squad. How many copper coils did each get? = 9 (G) · Head engineer filled 6 boxes with 8 microchips each, then found 26 more microchips. How many microchips are there in all? = 74 (S) · Head engineer collected 25 copper coils in the morning and 3 copper coils in the afternoon, then split them equally among 4 Robotics Squad. How many copper coils did each get? = 7 (A) · Head engineer collected 18 copper coils in the morning and 330 copper coils in the afternoon, then split them equally among 4 Robotics Squad. How many copper coils did each get? = 87 (N) · There were 413 gear wheels in all. 23 gear wheels were set aside. The rest were shared equally among 5 Robotics Squad. How many gear wheels did each get? = 78 (P) · Head engineer filled 3 boxes with 9 battery packs each, then found 33 more battery packs. How many battery packs are there in all? = 60 (T) · Head engineer earned 2 battery packs in each of 4 rounds, plus 55 bonus battery packs. Then 4 battery packs were lost. How many battery packs are left? = 59 (I)
- Clue 4 (Rounding): "WE FOUND NEON WIRES LEFT AT THE CRIME SCENE"Round 1,087 to the nearest hundred = 1100 (W) · Round 18 to the nearest ten = 20 (T) · Round 2,911 to the nearest hundred = 2900 (H) · Round 69 to the nearest ten = 70 (L) · Round 289 to the nearest ten = 290 (E) · Round 1,692 to the nearest hundred = 1700 (I) · Round 660 to the nearest hundred = 700 (N) · Round 2,315 to the nearest hundred = 2300 (U) · Round 2,254 to the nearest thousand = 2000 (F) · Round 110 to the nearest ten = 110 (O) · Round 905 to the nearest hundred = 900 (M) · Round 50 to the nearest ten = 50 (S) · Round 90 to the nearest ten = 90 (C) · Round 171 to the nearest ten = 170 (R) · Round 4,297 to the nearest hundred = 4300 (D) · Round 2,747 to the nearest thousand = 3000 (A)
- Clue 5 (Fractions of a number): surviving statement (box 4) → Bolt1/10 of 80 = 8 · 1/5 of 55 = 11 · 1/2 of 24 = 12 · 4/10 of 15 = 6 · 5/10 of 4 = 2 · 6/10 of 5 = 3 · 2/6 of 3 = 1 · 1/2 of 20 = 10 · 1/4 of 28 = 7 · 6/8 of 12 = 9 · 2/6 of 15 = 5
About this mystery
- Grade level
- Grade 4 math
- Math topics
- Fractions of a number, Multiplication, Multi-step word problems, Rounding
- Reading level
- grades 3-4
- Theme
- The Great Mech Workshop Mystery — set in Gearshift City Robotics Lab
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects