Two Plus Two Is Not Five: This is an awesome book. I bought the book the summer after my son’s kindergarten year. I wanted him to be able to add some of the smaller numbers without having to count on his fingers or draw stick figures. I switched some of the chapters around because he was grasping some concepts faster than others. When we got to the “trick” for Number in the Middle, I made a car game out of it, and began asking numbers in the middle as we were driving. Once he mastered that, I began using the practice worksheets. A huge success! I didn’t try to have my son master each “trick” in one sitting; we have paced his learning, and this summer we will be working on some other add and subtraction facts as well as moving into the multiplication book. I told all of my friends about the book, how it has enhanced my son’s ability to add and subtract with accuracy and speed as well as build his confidence in math. Lastly, his teacher told me that he was one of her brightest math students.