🔎 The titan cs50Grade 5Reading: grades 5-6AdditionSubtractionFractions of a numberMultiplication
The Sanders Theatre Server Sabotage
Oh no! A mysterious Rogue Compiler has locked down the CS50 grading servers right before the final project deadline. The Head Teaching Assistant has been locked out of the system. We must analyze the code logs, decrypt the network clues, and find out which campus coder is behind this cyber mischief before the submission portal closes forever!
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 | Glitch Attack | Cyber Trick | Keyboard Habit | Avatar Hair | Debugging Tool |
|---|---|---|---|---|---|
| Shannon | Buffer Overflow | Python Encryption | Right-handed typing | Sleek silver fiber hair | Rubber Duck Debugger |
| Turing | Stack Overflow | SQL Injection | Left-handed typing | Sleek silver fiber hair | Style50 Command |
| Diana | Memory Leak | Python Encryption | Left-handed typing | Neon blue terminal glow hair | Rubber Duck Debugger |
| Ada | Stack Overflow | Scratch Block Lock | Left-handed typing | Sleek silver fiber hair | Rubber Duck Debugger |
| Ritchie | Infinite Loop | Scratch Block Lock | Left-handed typing | Sleek silver fiber hair | Valgrind Memory Check |
| Colton | Buffer Overflow | Binary Override | Right-handed typing | Neon blue terminal glow hair | Style50 Command |
| Doug | Infinite Loop | C Pointer Hijack | Left-handed typing | Copper wire curls | Valgrind Memory Check |
| Margaret | Memory Leak | Python Encryption | Left-handed typing | Sleek silver fiber hair | Style50 Command |
| Grace | Stack Overflow | C Pointer Hijack | Left-handed typing | Neon blue terminal glow hair | Valgrind Memory Check |
| Hamilton | Stack Overflow | Binary Override | Left-handed typing | Sleek silver fiber hair | Style50 Command |
| Lovelace | Buffer Overflow | SQL Injection | Left-handed typing | Neon blue terminal glow hair | Style50 Command |
| Alan | Memory Leak | C Pointer Hijack | Right-handed typing | Neon blue terminal glow hair | Valgrind Memory Check |
| Torvalds | Memory Leak | Binary Override | Left-handed typing | Sleek silver fiber hair | Style50 Command |
| Babbage | Memory Leak | Scratch Block Lock | Right-handed typing | Sleek silver fiber hair | Style50 Command |
| Brian | Infinite Loop | Binary Override | Left-handed typing | Sleek silver fiber hair | Style50 Command |
| Hopper | Infinite Loop | C Pointer Hijack | Left-handed typing | Sleek silver fiber hair | Style50 Command |
| Wozniak | Syntax Error | C Pointer Hijack | Left-handed typing | Sleek silver fiber hair | Style50 Command |
| Carter | Infinite Loop | Scratch Block Lock | Left-handed typing | Copper wire curls | Style50 Command |
| Gates | Buffer Overflow | Python Encryption | Left-handed typing | Sleek silver fiber hair | Valgrind Memory Check |
| David | Buffer Overflow | C Pointer Hijack | Left-handed typing | Copper wire curls | Valgrind Memory Check |
| Berners | Memory Leak | Scratch Block Lock | Right-handed typing | Copper wire curls | Style50 Command |
Clue 1
Addition
We tallied up the total number of bug reports coming from the sandbox servers. Adding the freshman reports to the sophomore reports gave us the code we needed.
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
4451
6504
9359
9277
7175
2391
2391
7717
7175
3479
7988
8385
9359
4608
3479
8385
T
4451
9353
4608
9359
4855
7175
3479
7717
9526
3491
8385
9277
9359
9526
9526
7175
7988
9359
2059 + 2392 =T
3567 + 4421 =D
1712 + 1779 =Y
1397 + 3211 =S
3040 + 6313 =U
2424 + 1055 =N
3784 + 3933 =A
5062 + 4297 =E
1511 + 3344 =B
2954 + 4221 =I
3220 + 6306 =R
941 + 1450 =L
4368 + 2136 =H
4225 + 5052 =V
2556 + 5829 =O
0/15 letters found
Clue 2
Subtraction
The compiler erased several lines of our code. Subtracting the broken lines from the original file size left us with the secret key.
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
7660
5477
6520
1786
8168
1786
3639
6520
6291
T
7660
T
7660
4596
3639
6520
8733
7288
5115
2927
4596
5241
1606
T
7660
5477
T
7660
5477
6520
2927
6520
1795
T
7660
5477
6246
5115
8733
11897 - 4237 =T
8573 - 3096 =H
5273 - 1634 =P
9538 - 4297 =W
8623 - 455 =U
4823 - 3028 =F
13724 - 4991 =D
8957 - 1669 =O
6842 - 596 =A
2778 - 1172 =I
9220 - 2700 =E
5730 - 3944 =S
7413 - 2817 =Y
6456 - 3529 =L
6287 - 1172 =N
6676 - 385 =C
0/16 letters found
Clue 3
Fractions of a number
To unlock the memory banks, we had to analyze a batch of RAM chips. Exactly two thirds of the chips were corrupted by the rogue agent.
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
19
40
17
29
11
14
T
19
38
40
26
35
14
11
17
28
T
19
40
17
18
T
19
31
11
17
26
14
26
T
19
31
23
20
13
5/10 of 38 =T
2/10 of 115 =R
1/5 of 90 =S
1/5 of 100 =U
1/6 of 66 =L
3/6 of 34 =E
2/6 of 120 =H
4/5 of 35 =D
2/6 of 105 =A
2/10 of 155 =Y
1/4 of 152 =C
2/8 of 52 =N
5/10 of 52 =F
2/6 of 87 =G
2/8 of 56 =I
0/15 letters found
Clue 4
Multiplication facts (1-12)
The server room has a massive grid of glowing LED indicators. Multiplying the number of rows by the columns of green lights revealed the security bypass.
Solve each problem to learn its letter. Then write that letter in every box that shows the same number, and read the secret clue.
S
21
96
64
60
64
60
15
S
21
50
99
99
32
S
21
64
50
100
99
20
16
64
44
99
20
120
6
S
21
16
48
1
60
80
7 × 3 =S
8 × 12 =H
10 × 6 =N
4 × 8 =K
11 × 4 =B
3 × 5 =G
1 × 6 =A
10 × 2 =R
8 × 10 =D
6 × 8 =O
12 × 10 =W
1 × 1 =U
10 × 5 =L
11 × 9 =E
10 × 10 =V
8 × 8 =I
8 × 2 =F
0/17 letters found
Clue 5
Fractions of a number — the last clue
We sorted a stack of printed code pages into folders. Three fourths of the stack contained hidden instructions from the villain.
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
1/2 of 10 = ?
2/6 of 3 = ?
2/6 of 24 = ?
2/4 of 6 = ?
1/5 of 30 = ?
4/5 of 15 = ?
2/6 of 27 = ?
2/10 of 10 = ?
4/10 of 25 = ?
2/4 of 8 = ?
1/8 of 56 = ?
Step 2 — cross out the sentence with each answer
1.The villain triggered an infinite loop, then scrambled the memory logs with a c pointer hijack.
2.The villain threw a confusing syntax error, then locked down the servers with a scratch block lock.
3.The villain triggered an infinite loop, then bypassed security using a binary override.
4.The villain threw a confusing syntax error, then manipulated the grading system via sql injection.
5.The villain caused a massive memory leak, then sealed the database using python encryption.
6.The villain provoked a stack overflow, then sealed the database using python encryption.
7.The villain executed a buffer overflow, then locked down the servers with a scratch block lock.
8.The villain provoked a stack overflow, then manipulated the grading system via sql injection.
9.The villain executed a buffer overflow, then scrambled the memory logs with a c pointer hijack.
10.The villain caused a massive memory leak, then scrambled the memory logs with a c pointer hijack.
11.The villain threw a confusing syntax error, then scrambled the memory logs with a c pointer hijack.
12.The villain provoked a stack overflow, then locked down the servers with a scratch block lock.
Solve it
Name the culprit
Choose the one suspect left standing.
Answer Key — The Sanders Theatre Server Sabotage
Culprit: Wozniak (Syntax Error · C Pointer Hijack · Left-handed typing · Sleek silver fiber hair · Style50 Command)
- Clue 1 (Addition): "THE VILLAIN DOES NOT USE BINARY OVERRIDE"2059 + 2392 = 4451 (T) · 3567 + 4421 = 7988 (D) · 1712 + 1779 = 3491 (Y) · 1397 + 3211 = 4608 (S) · 3040 + 6313 = 9353 (U) · 2424 + 1055 = 3479 (N) · 3784 + 3933 = 7717 (A) · 5062 + 4297 = 9359 (E) · 1511 + 3344 = 4855 (B) · 2954 + 4221 = 7175 (I) · 3220 + 6306 = 9526 (R) · 941 + 1450 = 2391 (L) · 4368 + 2136 = 6504 (H) · 4225 + 5052 = 9277 (V) · 2556 + 5829 = 8385 (O)
- Clue 2 (Subtraction): "THE SUSPECT TYPED ONLY WITH THE LEFT HAND"11897 - 4237 = 7660 (T) · 8573 - 3096 = 5477 (H) · 5273 - 1634 = 3639 (P) · 9538 - 4297 = 5241 (W) · 8623 - 455 = 8168 (U) · 4823 - 3028 = 1795 (F) · 13724 - 4991 = 8733 (D) · 8957 - 1669 = 7288 (O) · 6842 - 596 = 6246 (A) · 2778 - 1172 = 1606 (I) · 9220 - 2700 = 6520 (E) · 5730 - 3944 = 1786 (S) · 7413 - 2817 = 4596 (Y) · 6456 - 3529 = 2927 (L) · 6287 - 1172 = 5115 (N) · 6676 - 385 = 6291 (C)
- Clue 3 (Fractions of a number): "THE GLITCH FAILED THE STYLE FIFTY RUN"5/10 of 38 = 19 (T) · 2/10 of 115 = 23 (R) · 1/5 of 90 = 18 (S) · 1/5 of 100 = 20 (U) · 1/6 of 66 = 11 (L) · 3/6 of 34 = 17 (E) · 2/6 of 120 = 40 (H) · 4/5 of 35 = 28 (D) · 2/6 of 105 = 35 (A) · 2/10 of 155 = 31 (Y) · 1/4 of 152 = 38 (C) · 2/8 of 52 = 13 (N) · 5/10 of 52 = 26 (F) · 2/6 of 87 = 29 (G) · 2/8 of 56 = 14 (I)
- Clue 4 (Multiplication facts (1-12)): "SHINING SLEEK SILVER FIBER WAS FOUND"7 × 3 = 21 (S) · 8 × 12 = 96 (H) · 10 × 6 = 60 (N) · 4 × 8 = 32 (K) · 11 × 4 = 44 (B) · 3 × 5 = 15 (G) · 1 × 6 = 6 (A) · 10 × 2 = 20 (R) · 8 × 10 = 80 (D) · 6 × 8 = 48 (O) · 12 × 10 = 120 (W) · 1 × 1 = 1 (U) · 10 × 5 = 50 (L) · 11 × 9 = 99 (E) · 10 × 10 = 100 (V) · 8 × 8 = 64 (I) · 8 × 2 = 16 (F)
- Clue 5 (Fractions of a number): surviving statement (box 11) → Wozniak1/2 of 10 = 5 · 2/6 of 3 = 1 · 2/6 of 24 = 8 · 2/4 of 6 = 3 · 1/5 of 30 = 6 · 4/5 of 15 = 12 · 2/6 of 27 = 9 · 2/10 of 10 = 2 · 4/10 of 25 = 10 · 2/4 of 8 = 4 · 1/8 of 56 = 7
About this mystery
- Grade level
- Grade 5 math
- Math topics
- Addition, Subtraction, Fractions of a number, Multiplication
- Reading level
- grades 5-6
- Theme
- The Sanders Theatre Server Sabotage — set in Sanders Theatre Server Room
- Format
- Interactive online & printable worksheet with answer key
- Solution
- One unique, verified culprit among 21 suspects