I am a teacher, and I looked at those lesson plans the last time this was in the news. Most of the lesson plans were crap--I fear for a world in which many teachers pay money for crap like that because they aren&#x27;t even able to make crap like that on their own.<p>The main reason I can neither be a customer nor a seller in a marketplace for teachers&#x27; lesson plans is that I use rarely used (that is, actually good) curricular materials for teaching mathematics at the &quot;prealgebra&quot; level,[1] and few other teachers use those. Most other teachers who do use the same materials I use are both smart enough to specify using those materials and smart enough to write their own lesson plans individualized for the classes they teach day by day.<p>[1] <a href="http:&#x2F;&#x2F;www.artofproblemsolving.com&#x2F;store&#x2F;item&#x2F;prealgebra" rel="nofollow">http:&#x2F;&#x2F;www.artofproblemsolving.com&#x2F;store&#x2F;item&#x2F;prealgebra</a><p><a href="http:&#x2F;&#x2F;www.amazon.com&#x2F;Math-Focus-Singapore-Teachers-Edition&#x2F;dp&#x2F;0547561008" rel="nofollow">http:&#x2F;&#x2F;www.amazon.com&#x2F;Math-Focus-Singapore-Teachers-Edition&#x2F;...</a>