We were in San Juan and a relative of our foster family had a trigonometry exam the next day. It was really bad because he doesn't only have a good grasp of basic algebra (crucial for trigo) but also has problems understanding the problems themselves. The problem set he was answering were naturally in English. He didn't even know what a ladder or a lighthouse is. Given that a beginner usually needs to draw a trigo problem before solving it, he was almost a hopeless case. I understood then why many people prefer to teach in science high schools or UP than in other places.