Suitable for 7th/8th grade pre-algebra. Students often make small mistakes in various steps in solving an equation, and this practice material teaches them to be sensitive to those mistakes, and helps them learn to avoid them. Parents or teachers can use this material equally well. I find that many middle school teachers miss out on a great opportunity to create non-traditional types of materials to enhance learning. Most teachers give the same usual dry "solve for x" types of questions, and kids continue making mistakes. I'm a strong believer in giving the right kinds of targeted practice materials to enable kids to fine-tune their abilities, or to help struggling kids find a way to get good at this material.