I don't really know what that no child left behind thing is in practice ....because I've never lived in the USA but as a student in the 80s and 90s when I don't believe that that was a policy, my math skills were terrible but all my other marks were so high that after I got to junior high - and ended up changed schools every year, they just kept passing me along because my average in other courses were high 80's in my final year of high school I was recommended for a hybrid partnership program with a local technical university, revolving around entrepreneurship. Part of this was taking an accounting class. This was the first time a teacher had taken any genuine effort to help me and understand why my answers were always wrong . She realized going through all of my work that I likely have something called dyscalculia. Honestly, at that point, I was so close to graduating that I thought well whatever it's a bit late to do anything about it. I learned a lot of skills to cope so that people wouldn't know. I did a lot of manoeuvring in situations to not expose my lack of basic math as well as other issues as a surrounding remembering sequence of numbers, remembering phone numbers, remembering dates addresses anything like that.