AP Computer Science Principles 3-Day Cram Plan

You have three days until the AP Computer Science Principles exam. This is not about learning to code — it's about mastering AP Pseudocode, locking in the 5 Big Ideas structure, and drilling the 70-question MCQ patterns that repeat every year.

This plan assumes ~4 focused hours per day. The exam is 70% MCQ (70 questions, 2 hours) + 30% Create Performance Task (already submitted). Skip nothing on this checklist.

Day 1: Pseudocode Basics + Big Ideas 1-2 (4 hrs)

The first 20 MCQ questions test whether you can read pseudocode. Get this automatic.

What to review (90 min)

AP Pseudocode essentials:

• Assignment: a ← 5 or name ← "Alice"
• Display/Input: DISPLAY(message), INPUT()
• If/Else: IF (condition) { ... } ELSE { ... }
• Repeat: REPEAT n TIMES { ... } or REPEAT UNTIL (condition) { ... }
• For Each: FOR EACH item IN list { ... }
• Procedures: PROCEDURE name(param1, param2) { ... }
• Lists (1-indexed): INSERT(list, index, value), APPEND(list, value), REMOVE(list, index), LENGTH(list)

Big Idea 1 — Creative Development:

• Program purpose vs function
• Collaboration, debug strategies, iterative design

Big Idea 2 — Data:

• Binary numbers (2-bit, 8-bit, ASCII)
• Lossy vs lossless compression (JPEG vs PNG)
• Data abstraction, metadata, privacy

What to practice (2.5 hrs)

• Trace 10 pseudocode snippets (assignments, loops, conditionals). Write outputs.
• 5 MCQ on binary conversion (decimal ↔ binary, bit/byte sizes).
• 3 MCQ on lossy vs lossless (identify which compression method).

💡 Highest leverage: Trace one 10-line pseudocode block per day cold. Most students skip this and lose 8-10 points on Day 3.

Day 2: Big Idea 3 — Algorithms & Programming (4 hrs)

This covers ~40% of the exam. Master it.

What to review (90 min)

Variables and data types:

• Assignment, list creation, procedure parameters
• Variable scope (local vs global)

Control flow:

• Sequencing: order matters
• Selection: IF/ELSE branches
• Iteration: loops and their uses

Lists and traversal:

• Index access list[i]
• INSERT, APPEND, REMOVE, LENGTH
• Loop through list with FOR EACH item IN list
• Search and sort conceptually (don't need to code; recognize the algorithm)

Procedures and abstraction:

• Procedural abstraction: breaking a task into a reusable procedure
• Identifying what a procedure does from its code
• Parameters, return values (procedures return a value with RETURN value)

Undecidable problems & algorithmic efficiency:

• Undecidable = no algorithm can solve it in finite time for all cases (e.g., halting problem)
• Sequential vs parallel computing
• Scalability, redundancy, fault tolerance

What to practice (2.5 hrs)

• Trace a 15-line pseudocode procedure with a list (loop, conditional, APPEND).
• 12 MCQ: trace code, identify bugs, determine output
• 3 MCQ: identify which procedure abstracts a task correctly
• 2 MCQ: classify a problem as decidable/undecidable

⚠️ Trap: When tracing a loop with an index, track the variable value after each iteration. Write it down. Most errors come from losing track of the counter.

Day 3: Big Ideas 4-5 + Full MCQ Set (4 hrs)

What to review (90 min)

Big Idea 4 — Computer Systems & Networks:

• Internet: packet switching, redundancy, scalability
• Packets, protocols, DNS, routing
• Fault tolerance: multiple paths, backup systems
• Bandwidth, latency, throughput

Big Idea 5 — Impact of Computing:

• Digital divide (access gaps)
• Beneficial innovations (medical, communication) vs harmful (surveillance, misinformation)
• PII (personally identifiable information), multi-factor auth, encryption (symmetric vs asymmetric)
• Phishing, malware, crowdsourcing, citizen science
• Computing bias, intellectual property, cybersecurity

What to practice (2.5 hrs — full timed set)

• 25 mixed MCQ from Big Ideas 4-5 (networks, Internet, cybersecurity, impact)
• 20 pseudocode tracing + algorithm MCQ (mix of Big Ideas 2-3)
• 15 review MCQ: your weakest areas from Days 1-2

🎯 Scoring target: 50+ on 70 MCQ = 71% correct. You can skip 20 and still hit a 5 (rough).

Create Performance Task (CPT) — Your hidden advantage

You already submitted your CPT video and written response before exam day. Some MCQ questions will reference pseudocode similar to your program. Review:

• What your program does (its purpose)
• The main data structures you used (lists, variables)
• Your biggest procedures
• Any list traversal or conditional logic you wrote

You don't need to defend your CPT on the exam, but recognizing your own patterns in MCQ code snippets can unlock 2-4 easy points.

Common point-leaks

• Confusing 0-indexed and 1-indexed lists. AP Pseudocode lists are 1-indexed (first item is list[1], not list[0]).
• Forgetting to trace the loop. Write down variable values after each iteration.
• Skipping "what does this procedure do?" questions. Read the code first; match it to a real-world task.
• Guessing on encryption/security. Know symmetric (same key) vs asymmetric (public/private key).
• Misidentifying lossy vs lossless. JPEG = lossy (removes data, smaller file). PNG = lossless (preserves all).

The night before

Skim the last-minute review checklist. Get 8 hours of sleep — pseudocode tracing requires mental clarity.

Ready to start?

Open the AP CSP topic library → or dive into the MCQ practice guide →. Start with Day 1 pseudocode tracing. You've got this. 🎯