10 Most Common Mistakes Students Make on the Upper Level ISEE

The Upper Level ISEE (for students applying to grades 9–12) is one of the most challenging admissions exams students face. With advanced vocabulary, dense reading passages, and math that spans algebra, geometry, and multi-step word problems, even strong students can get caught off guard.

Here are the 10 most common mistakes students make on the Upper Level ISEE—and how to avoid them.

1. Treating the ISEE Like a School Test

Many students walk into the exam expecting familiar formats and straightforward questions. But the ISEE tests how students think, not just what they’ve learned in class. The questions are designed to be trickier, more abstract, and more reasoning-based than typical schoolwork. Students who rely on memorized formulas or assume everything will look familiar often feel blindsided.

How to avoid it: Practice with ISEE-style questions early so the structure becomes familiar.

2. Running Out of Time

Upper Level timing is tight—and students often underestimate how quickly they need to move. Some spend several minutes wrestling with a tough question, only to realize they’ve sacrificed easier questions at the end. Poor pacing can drop a student’s score dramatically, even if they know the material well.

How to avoid it: Use a watch, set pacing goals, and learn when to move on. The best test-takers know when not to fight a problem.

3. Letting Vocabulary Sink the Verbal Section

The vocabulary used in the Upper Level ISEE is intentionally advanced, often including college-level or SAT-level words. Students who rely solely on memorizing lists end up stuck when faced with unfamiliar choices. Many strong readers freeze when confronted with multiple plausible answers.

How to avoid it: Learn root words, prefixes, suffixes, and context-clue strategies. Memorization alone won’t cut it.

4. Overthinking Quantitative Reasoning

Students often attack the Quantitative Reasoning section like a math test—writing equations, doing long calculations, or forcing algebra onto logic problems. In reality, many questions are designed to be solved quickly through reasoning, estimation, or pattern recognition. Overthinking wastes time and increases errors.

How to avoid it: Look for patterns, estimation, and quick comparisons. The simplest path is often the correct one.

5. Not Reading Carefully in the Reading Section

Upper Level reading passages are dense, complex, and vocabulary-heavy. Students who skim miss key details, while students who read too slowly run out of time. Many lose points on inference and tone questions because they focus on literal meaning rather than the deeper intention.

How to avoid it: Use quick annotation strategies and read just deeply enough—not too slow, not too fast.

6. Weaknesses in Algebra and Geometry Foundations

By the Upper Level, math expectations are high. Students who never mastered fractions, integers, exponents, solving equations, or basic geometry suddenly hit a wall. Even small foundational gaps lead to big losses in the Math Achievement section, which is heavily computation-based.

How to avoid it: Strengthen fundamentals before tackling advanced problems. A tutor can quickly identify and close skill gaps.

7. Not Showing Work or Using Scratch Paper Incorrectly

Upper Level problems require multiple steps, and students who write down cramped or messy notes often lose track of their work. They copy numbers incorrectly, skip steps, or make simple arithmetic mistakes because their scratch paper becomes chaotic.

How to avoid it: Use organized scratch paper: label sections, rewrite key numbers clearly, and structure your steps.

8. Freezing During the Essay

The timed essay can intimidate even excellent writers. Students often panic trying to think of the “perfect” example or get stuck rewriting their opening sentence repeatedly. Without a simple structure to rely on, they waste precious minutes and end up rushing the final paragraphs.

How to avoid it: Learn a simple essay structure and practice 5-minute outlines. A decent, complete essay beats an excellent, unfinished one.

9. Letting One Bad Question “Spiral” Into More Mistakes

When students encounter a hard question early, they often panic. This can trigger a chain reaction—self-doubt, rushing, careless mistakes, and loss of focus. One tough moment can derail an entire section if students don’t reset quickly.

How to avoid it: Adopt the mindset: One question doesn’t define the test. Take a breath, reset, and move on.

10. Not Taking Full-Length Practice Tests

Many students only practice isolated problems or short sections. Then, on test day, they are shocked by the mental stamina required for a nearly three-hour exam. Without practice sitting for the full duration, pacing and focus break down by the final sections.

How to avoid it: Take full-length practice exams, ideally in a quiet environment with a timer. This builds endurance and familiarity with the test flow.

The Upper Level ISEE is challenging—but every mistake on this list is avoidable with the right preparation. When students understand the format, build foundational skills, and learn strategic pacing, their confidence skyrockets.

At LA Math Tutoring, we help students master each section through individualized prep plans, timed practice, and expert guidance. With the right support, students can walk into test day feeling calm, capable, and ready to excel.