Review on Channies Problem Workbook Prek 1st Repetition: Enhance Learning and Retention by Bobby Martinez

My son started kindergarten this year. He's very good at addition and subtraction, so I wanted to give him some work after his typical kindergarten math class. I like this book not only for practice, but also because I can show him how to organize his math into columns so he doesn't lose track of where he is in the problem.