In fact, the content of primary school mathematics is very simple, and the lengthy supplementary books are also designed to give consideration to students with good grades and poor grades, so that they can have a more thorough understanding of knowledge, but they are often jumbled and unclear. I went to the bookstore to buy counseling books before. After comparison, I found that most of the explanations in the textbook help are presented in the form of block diagrams and flowcharts, which are very clear and clear at a glance. I bought a set for my brother, and now he has reviewed it well with preview. I recommend it to you. I hope your children can also benefit.