kraftiekortie is almost definitely right. There's a math competition called the AMC10, which takes place annually. I took it last year as well as this year, and I did way worse on it this year than I did last year. It's possible that I've gotten worse at math in the past year. But on the day of the test, I was tired, and I was in the middle of a very stressful and crazy couple of months, so I couldn't concentrate very well. Really, extraneous factors affect test scores so much, I wouldn't worry about it. I agree that you should definitely try to retake the test (but make sure you're well-rested!)
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