I wish I knew the redditor's username to properly acknowledge their kindness, but I hope the masterlist will do that for me later on. This will have to do for now.

This amazing text is not part of the required text in my middle school mathematics curriculum. However, I did stumble upon it as a powerful way of improving number sense, basic skills, word problem, and deep critical thinking skills in Math class. Typically, students entering my classroom start with poor number sense as a result of low math background in the difficult environment of inner city urban schooling. I am so grateful to my kind educational Santa for this gift which was difficult for me to dig into my pockets for.

2 weeks into the school year, and it's already helped me develop more effective lessons in modeling percents and solving real world problems involving percent changes. This is not in any way a simple mechanical method of doing math, but rather a deeper, diverse set of approaches to find solutions. I've attached a few photos which, if interpreted carefully, shows nice math thinking with efficiency.