Writing standard: When using the horizontal grid in the math exercise book (horizontal grid book) (1), it should be noted that there should be a certain gap between the upper edge and the lower edge of words, and there should be an appropriate distance between words. Try to make the payment clean and tidy.

(2) The first line indicates the date, and the second line indicates the number of pages and the title.

(3) After each question is finished, leave a blank before doing the next question.

(4) Before each question, correct the wrong questions in front, and the position should be after the current homework, and indicate the word "modified".