Tohyama Hiroshi's "Arithmetic Exploration" 10-volume set is for sale. 1 volume list price: 3,600 yen (excluding tax) x 10 volumes. I purchased this used several years ago, but it has been sitting on the bookshelf unused. Most volumes still have the tags attached, so you can imagine the condition of the product. This book is often advertised in the Nikkei newspaper, etc. How about it as a gift for children or grandchildren for their entrance into school? Please note that there is no included box, so the 10 books will be bundled and shipped in cardboard, etc. This is a used item, so please purchase if you understand this.