Not difficult. From the comparison of my use, this book should be prepared for the top 20% children. Of course, the top 50% children can also use it, because it has a synchronous training part, which is not difficult for most students. But I still think the author's real intention is to write a set of teaching AIDS for children who pay 20%.

Compared horizontally, the difficulty of this book should be equal to or slightly higher than the A version of the primary school Olympic Games published by Shaanxi People's Education Publishing House. By the way, the A version of the primary school Olympic Games is still a good teaching aid, but there is no sub-version. This requires the reader to judge whether to use it. Judging from the topic design, training intensity and quality, it is still worth using.