I should know, I do it everyday at school. Lol
Friv have a school version which doesn't get blocked (I can't remember what it's called right now but I'll add it in when I do) or coolmathgames. They're not maths games, but because the website has 'math' in it, it usually isn't blocked. Thee are a few others, too,but if you search for a game and try a few sites, you should find some ones that work :)
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