Most points lost on the AMC are not lost to hard problems. They are lost to avoidable habits.
The American Mathematics Competitions (AMC), run by the Mathematical Association of America, are the entry point to the U.S. olympiad pathway. The AMC 8 is a 25-question, 40-minute contest for students in grade 8 and below. The AMC 10 and AMC 12 are 25-question, 75-minute contests, each offered in an "A" and a "B" version, for students in grade 10 and below and grade 12 and below respectively. Strong AMC 10/12 scorers earn an invitation to the AIME. Below are the most common AMC mistakes we see students make, and how to fix each one.
Strategy and Scoring Mistakes
The single most important thing to understand about the AMC 10 and AMC 12 is the scoring rule. A correct answer earns 6 points, a blank earns 1.5 points, and a wrong answer earns 0. That structure changes how you should play the game.
- Guessing blindly. Because a blank is worth 1.5 points and a wrong answer is worth nothing, random guessing on the AMC 10/12 actively lowers your expected score. Only guess when you can confidently eliminate at least two of the five choices.
- Refusing to skip. A problem you cannot solve in a reasonable time should be left for later or left blank. The contest does not reward stubbornness. Treat strategic skipping as a skill to practice, not just understand.
- Chasing the hard problems first. Question 3 is worth exactly as many points as question 23. Spending ten minutes on a late problem while a careless error sits on an early one is a poor trade.
Note: the AMC 8 uses a simpler scoring system without the blank-answer bonus, so guessing logic differs. Always confirm the current rules for your specific contest on the official MAA AMC page before test day.
Careless and Reading Mistakes
When students review their own results, errors tend to fall into three buckets: a topic gap (you did not know the method), a careless error (you knew the method but slipped), and a strategy error (you guessed when you should have skipped). On the early problems, careless errors dominate.
Rushing the easy questions
Students often sprint through the first 10 to 15 questions assuming they are trivial, then drop points to arithmetic slips and misreads. Slow down just enough to be sure. The early problems are where your highest-value, lowest-risk points live.
Misreading the question
Answering for x when the problem asks for x + 1, or for the perimeter when it asks for the area, is heartbreakingly common. Underline what the question actually wants before you start, and check that your final answer matches the units and form requested.
Bubbling errors
On a multiple-choice test, transcribing the wrong letter wastes a problem you actually solved. Mark answers carefully and leave a few minutes at the end to verify your sheet against your work.
Preparation Mistakes
The habits that hurt on test day usually start during preparation. A few patterns to avoid:
- Doing problems without timing them. The AMC is as much a clock-management test as a math test. Practice under realistic time limits so pacing becomes automatic.
- Never reviewing wrong answers. Past contests are freely available, but they only help if you analyze every miss and label it as a topic gap, a careless error, or a strategy error. The label tells you what to fix.
- Sitting the wrong contest. The AMC 10 excludes trigonometry, advanced algebra, and advanced geometry, while the AMC 12 covers the full high school curriculum short of calculus. Eligible students should choose deliberately rather than by default.
- Studying in isolation. Working through problem sets with stronger peers and a coach exposes blind spots faster than solo grinding. Our AMC preparation track and structured math program are built around timed practice and targeted review of exactly these error types.
One more reminder: do not anchor on a specific score cutoff. AIME invitations go to roughly the top 2.5% of AMC 10 scorers and the top 5% of AMC 12 scorers, but the numerical threshold shifts every year with the difficulty of the test. Aim to maximize accuracy and clean execution rather than hitting a fixed number.
The students who improve fastest are not the ones who memorize more formulas. They are the ones who stop repeating the same three mistakes.
Ready to turn these fixes into a real score gain? Explore the full range of competitions BIAA prepares students for and find the right starting point for your student today.