How to Eliminate Careless Mistakes on the GMAT

“You should actually get a little bit excited when you make a careless mistake—because you’re about to get better.”

Everyone makes careless mistakes on the GMAT—even well-prepared test takers. In this episode of Inside the GMAT, GMAC Zach sits down with Manhattan Prep instructor Stacey Koprince to break down why these mistakes happen and what you can actually do to prevent them.

Stacey explains the critical difference between a true knowledge gap and a careless mistake—and why the latter is often the easiest type of mistake to fix. Instead of beating yourself up when you spot one, she argues you should see it as an opportunity to improve your score.

The conversation explores the hidden causes behind careless errors, including stress, mental fatigue, time pressure, and small weaknesses in your knowledge foundation. Zach and Stacey also discuss practical strategies for identifying patterns in your mistakes and building new habits that interrupt them before they happen again.

Listeners will learn how to use a review log (AKA error log) to track mistakes, how to diagnose the real reason an error occurred, and how to design simple “micro-checks” during problem solving that can prevent costly slip-ups.

They also tackle an uncomfortable truth about adaptive exams like the GMAT: sometimes the smartest strategy is getting questions wrong quickly so you can protect your accuracy on questions you can get right.

If you’ve ever finished a problem, looked at the correct answer, and thought “I knew that—how did I miss it?”, this episode will give you a framework for turning those frustrating moments into real score gains.

About Stacey:

Stacey Koprince is one of the most recognized names in test prep, with over 15 years of experience teaching the GMAT, EA, GRE, and LSAT. As Manhattan Prep’s Director of Content & Curriculum, she has written countless articles, guides, and video explanations that thousands of students rely on. A former management consultant, Stacey now spends her days helping future business leaders master tricky concepts and find confidence in their prep—something she’s passionate about seeing “click” for every student.

Helpful links:

Register for the GMAT: https://www.mba.com/exams/gmat-exam/register

Purchase GMAT Official Prep: https://www.mba.com/exams/executive-assessment/prepare

GMAC Official Starter Kit (FREE): https://www.mba.com/exam-prep/gmat-official-starter-kit

Manhattan Prep Official Starter Kit (FREE): https://www.kaptest.com/gmat/free/gmat-practice

Inside the GMAT/GMAC Zach on Substack: https://substack.com/@gmaczach

Key Takeaways:

• Careless mistakes aren’t random—they usually follow personal patterns you can identify and fix.

• The process to fix them: identify the mistake → understand why it happened → build a new habit to prevent it.

• Small habits (like writing key information on scratch paper) can dramatically reduce errors.

• Keeping a review log helps reveal patterns across practice sessions.

• On adaptive exams, time management matters: sometimes it's smarter to guess quickly and protect accuracy elsewhere.

Chapters:

00:00 Introduction to Careless Mistakes
05:04 Identifying Patterns in Mistakes
11:12 Types of Careless Mistakes
16:50 The Importance of a Review Log
24:02 Introduction to Effective Study Habits
27:53 Balancing Speed and Accuracy in Test Taking
34:46 Understanding and Managing Time During Tests
42:32 Finding the Right Balance in Test Taking