At BetterLesson[1], we have found them and made all their excellent lessons available online for free (Grades K-12). These lessons are mainly for teacher consumption, but have some great teaching strategies for all to learn. Some examples: http://betterlesson.com/lesson/432502/intro-to-trigonometry-... http://betterlesson.com/lesson/448934/adding-and-subtracting...

[1] http://betterlesson.com/master_teacher_projects