How much does it cost to buy a math reference book for the college entrance examination from junior high school?
40 yuan can be counted as one (there are two CDs in the current math reference books), six in junior high school and six in senior high school, totaling 12.
12×40=480 yuan, but this kind of books is not easy to buy, you can consult Xinhua Bookstore.
In addition, the textbooks are often reformed now, and your junior high school textbooks are used up. Maybe the high school textbook has been changed.