Art of Problem Solving MathCounts Trainer: https://aops.com/mc
Art of Problem Solving the Win (live countdown round): https://artofproblemsolving.com/ftw
Old MathCounts tests: https://mathteamnyc.weebly.com/mathcounts.html
Old AMC 8/10/12: https://mathwo.github.io/coverpages/2020-11-11-books-and-resources
Generate MathCounts Practice Tests: http://mathcounts.saab.org/mc.cgi
If you use this one online, you can retake the test with different numbers (but the same questions) to make sure you understand the concepts.
MathCounts Bible Flash Cards: https://quizlet.com/1771919/mathcounts-bible-flash-cards/
OJH Math Team 