🤖 RobotsGrade 2Reading: grades 1-2Place valueAdditionSubtractionMultiplicationMissing addends
The Mystery of the Golden Wrench
A wild rogue bot ran away with the golden wrench. We must look at the scrap parts and track them down before they build a giant rust monster.
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 Engine | Special Tool | Blinker Side | Head Piece | System Halt |
|---|---|---|---|---|---|
| Ada | laser eyes | buzzer nose | left-side blinker | silver foil spikes | loud music beats |
| Lovelace | wheel feet | buzzer nose | right-side blinker | blue plastic dome | loud music beats |
| Widget | magnet hands | drill arms | right-side blinker | blue plastic dome | strong fridge magnets |
| Bolt | springy legs | solar wings | left-side blinker | copper wire tuft | strong fridge magnets |
| Nutty | springy legs | crane hook | left-side blinker | silver foil spikes | strong fridge magnets |
| Clanky | magnet hands | buzzer nose | left-side blinker | silver foil spikes | strong fridge magnets |
| Byte | springy legs | crane hook | right-side blinker | silver foil spikes | strong fridge magnets |
| Vector | rocket boots | drill arms | left-side blinker | silver foil spikes | strong fridge magnets |
| Marvin | springy legs | crane hook | left-side blinker | copper wire tuft | strong fridge magnets |
| Gizmo | rocket boots | radar ears | left-side blinker | silver foil spikes | strong fridge magnets |
| Chip | magnet hands | drill arms | left-side blinker | silver foil spikes | strong fridge magnets |
| Gearbox | rocket boots | solar wings | left-side blinker | silver foil spikes | sticky oil puddles |
| Robbie | springy legs | solar wings | right-side blinker | silver foil spikes | strong fridge magnets |
| Sparky | springy legs | solar wings | left-side blinker | silver foil spikes | sticky oil puddles |
| Boop | springy legs | radar ears | right-side blinker | copper wire tuft | strong fridge magnets |
| Watson | wheel feet | radar ears | left-side blinker | blue plastic dome | sticky oil puddles |
| Beep | rocket boots | solar wings | right-side blinker | copper wire tuft | loud music beats |
| Sprocket | magnet hands | crane hook | left-side blinker | blue plastic dome | loud music beats |
| Isaac | wheel feet | drill arms | right-side blinker | blue plastic dome | loud music beats |
| Asimov | magnet hands | buzzer nose | left-side blinker | silver foil spikes | sticky oil puddles |
| Turing | rocket boots | crane hook | right-side blinker | blue plastic dome | strong fridge magnets |
Clue 1
Place value
We found a broken screen. The numbers on it show the bot ID.
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
39
78
54
12
61
90
80
54
27
61
T
39
84
61
54
32
88
61
T
39
78
47
64
54
47
27
80
52
52
54
12
88
61
32
54
What number has 3 tens and 9 ones?T
What number has 1 ten and 2 ones?R
What number has 9 tens and 0 ones?G
What number has 2 tens and 7 ones?B
What number has 6 tens and 1 one?O
What number has 8 tens and 8 ones?N
What number has 6 tens and 4 ones?V
What number has 7 tens and 8 ones?H
What number has 3 tens and 2 ones?S
What number has 5 tens and 4 ones?E
What number has 5 tens and 2 ones?Z
What number has 8 tens and 0 ones?U
What number has 4 tens and 7 ones?A
What number has 8 tens and 4 ones?D
0/14 letters found
Clue 2
Addition
We counted the rusty bolts in two piles to find the code.
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
80
58
98
55
59
51
38
38
38
A
80
58
A
80
71
62
98
59
83
51
75
29
59
55
66
51
62
51
33
55
38
98
56
51
50 + 30 =A
21 + 34 =T
40 + 18 =W
31 + 25 =D
8 + 21 =O
31 + 35 =H
59 + 39 =I
45 + 30 =R
22 + 49 =B
26 + 25 =E
38 + 24 =L
49 + 34 =K
20 + 13 =F
27 + 11 =S
36 + 23 =N
0/15 letters found
Clue 3
Subtraction
The power tank lost some oil. We subtracted to see the leak.
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
46
64
39
44
34
T
46
85
72
84
84
T
46
60
53
75
T
46
34
84
T
46
69
34
35
71
21
69
77
65
71
39
30
72
71
35
39
T
46
84
69 - 23 =T
96 - 19 =I
44 - 10 =O
73 - 4 =R
102 - 31 =G
63 - 33 =M
93 - 33 =U
73 - 9 =H
57 - 22 =N
74 - 30 =B
111 - 36 =K
91 - 19 =A
89 - 4 =W
93 - 9 =S
55 - 34 =F
73 - 20 =C
88 - 23 =D
73 - 34 =E
0/18 letters found
Clue 4
Multiplication facts (1-12)
The robot charging station has four rows of plugs.
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
45
66
63
20
27
T
45
25
88
27
48
48
63
25
100
10
16
50
63
88
60
27
10
16
100
48
10
4
63
100
66
63
88
63
9 × 5 =T
8 × 2 =L
4 × 1 =K
10 × 10 =S
5 × 2 =I
3 × 9 =O
8 × 6 =P
7 × 9 =E
6 × 11 =H
6 × 10 =F
5 × 10 =V
5 × 5 =D
5 × 4 =B
8 × 11 =R
0/14 letters found
Clue 5
Missing addends — the last clue
We need ten gear teeth. We have some but we need more.
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
4 + ___ = 9
3 + ___ = 6
7 + ___ = 15
6 + ___ = 13
10 + ___ = 21
10 + ___ = 14
7 + ___ = 9
8 + ___ = 9
1 + ___ = 10
2 + ___ = 12
1 + ___ = 13
Step 2 — cross out the sentence with each answer
1.The villain rolls down the main hallway on fast wheel feet, then finds the secret exit using radar ears.
2.The villain leaps over the security gate with springy legs, then makes a loud honking sound with a buzzer nose.
3.The villain flies through the skylight using rocket boots, then finds the secret exit using radar ears.
4.The villain rolls down the main hallway on fast wheel feet, then digs a tunnel through the floor with drill arms.
5.The villain leaps over the security gate with springy legs, then swings up to the ceiling on a crane hook.
6.The villain flies through the skylight using rocket boots, then digs a tunnel through the floor with drill arms.
7.The villain zaps the vault door with hot laser eyes, then finds the secret exit using radar ears.
8.The villain snatches the metal safe with magnet hands, then digs a tunnel through the floor with drill arms.
9.The villain leaps over the security gate with springy legs, then finds the secret exit using radar ears.
10.The villain flies through the skylight using rocket boots, then glides away into the clouds with solar wings.
11.The villain rolls down the main hallway on fast wheel feet, then makes a loud honking sound with a buzzer nose.
12.The villain zaps the vault door with hot laser eyes, then makes a loud honking sound with a buzzer nose.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Mystery of the Golden Wrench
Culprit: Vector (rocket boots · drill arms · left-side blinker · silver foil spikes · strong fridge magnets)
- Clue 1 (Place value): "THE ROGUE BOT DOES NOT HAVE A BUZZER NOSE"What number has 3 tens and 9 ones? = 39 (T) · What number has 1 ten and 2 ones? = 12 (R) · What number has 9 tens and 0 ones? = 90 (G) · What number has 2 tens and 7 ones? = 27 (B) · What number has 6 tens and 1 one? = 61 (O) · What number has 8 tens and 8 ones? = 88 (N) · What number has 6 tens and 4 ones? = 64 (V) · What number has 7 tens and 8 ones? = 78 (H) · What number has 3 tens and 2 ones? = 32 (S) · What number has 5 tens and 4 ones? = 54 (E) · What number has 5 tens and 2 ones? = 52 (Z) · What number has 8 tens and 0 ones? = 80 (U) · What number has 4 tens and 7 ones? = 47 (A) · What number has 8 tens and 4 ones? = 84 (D)
- Clue 2 (Addition): "A WITNESS SAW A BLINKER ON THE LEFT SIDE"50 + 30 = 80 (A) · 21 + 34 = 55 (T) · 40 + 18 = 58 (W) · 31 + 25 = 56 (D) · 8 + 21 = 29 (O) · 31 + 35 = 66 (H) · 59 + 39 = 98 (I) · 45 + 30 = 75 (R) · 22 + 49 = 71 (B) · 26 + 25 = 51 (E) · 38 + 24 = 62 (L) · 49 + 34 = 83 (K) · 20 + 13 = 33 (F) · 27 + 11 = 38 (S) · 36 + 23 = 59 (N)
- Clue 3 (Subtraction): "THE BOT WAS STUCK TO STRONG FRIDGE MAGNETS"69 - 23 = 46 (T) · 96 - 19 = 77 (I) · 44 - 10 = 34 (O) · 73 - 4 = 69 (R) · 102 - 31 = 71 (G) · 63 - 33 = 30 (M) · 93 - 33 = 60 (U) · 73 - 9 = 64 (H) · 57 - 22 = 35 (N) · 74 - 30 = 44 (B) · 111 - 36 = 75 (K) · 91 - 19 = 72 (A) · 89 - 4 = 85 (W) · 93 - 9 = 84 (S) · 55 - 34 = 21 (F) · 73 - 20 = 53 (C) · 88 - 23 = 65 (D) · 73 - 34 = 39 (E)
- Clue 4 (Multiplication facts (1-12)): "THE BOT DROPPED SILVER FOIL SPIKES HERE"9 × 5 = 45 (T) · 8 × 2 = 16 (L) · 4 × 1 = 4 (K) · 10 × 10 = 100 (S) · 5 × 2 = 10 (I) · 3 × 9 = 27 (O) · 8 × 6 = 48 (P) · 7 × 9 = 63 (E) · 6 × 11 = 66 (H) · 6 × 10 = 60 (F) · 5 × 10 = 50 (V) · 5 × 5 = 25 (D) · 5 × 4 = 20 (B) · 8 × 11 = 88 (R)
- Clue 5 (Missing addends): surviving statement (box 6) → Vector4 + ___ = 9 = 5 · 3 + ___ = 6 = 3 · 7 + ___ = 15 = 8 · 6 + ___ = 13 = 7 · 10 + ___ = 21 = 11 · 10 + ___ = 14 = 4 · 7 + ___ = 9 = 2 · 8 + ___ = 9 = 1 · 1 + ___ = 10 = 9 · 2 + ___ = 12 = 10 · 1 + ___ = 13 = 12
About this mystery
- Grade level
- Grade 2 math
- Math topics
- Place value, Addition, Subtraction, Multiplication, Missing addends
- Reading level
- grades 1-2
- Theme
- The Mystery of the Golden Wrench — set in The Bolt-Cove Repair Bay
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects