A large share of the points students lose on AMC 8 and AMC 10 don't come from problems they genuinely couldn't solve — they come from a handful of repeatable, avoidable mistakes.
Mistake 1: Poor Time Allocation
Spending too long on an early, harder-than-expected question can leave too little time for easier questions later in the paper. Since questions are only loosely ordered by difficulty, a rigid "solve in order" approach often costs more than it helps.
Mistake 2: Ignoring Answer Choices
Multiple-choice format is a resource, not just a constraint — process of elimination, working backward from answer choices, and estimating are all legitimate, fast strategies that students who only practice free-response problems often forget to use.
Mistake 3: Guessing Without Any Elimination (AMC 10)
On AMC 10, guessing blindly among all five options has a lower expected value than leaving a question blank. Students who bring an "always attempt everything" instinct from school exams often lose points this way without realizing the scoring works differently.
Mistake 4: Careless Arithmetic Under Time Pressure
Since calculators aren't allowed, small arithmetic slips under time pressure are a common, avoidable source of lost points — particularly on problems the student conceptually understood perfectly well.
Mistake 5: Not Reviewing Wrong Answers Afterward
Moving on to the next practice paper without understanding exactly why a mistake happened — a content gap, a careless error, a time-pressure decision — means the same mistake tends to repeat across multiple attempts.