First of all, Baidu searched the teaching network and entered the teaching network official website. Pay attention to the subject navigation on the left, move the mouse to the primary school mathematics subject, and select the People's Education Edition. At this point, move the mouse to the version level here, click and select the version level you want. What I choose here is the first volume of the third grade of the People's Education Edition. After pressing OK, you will see the following page. For the chapter in the unit on the left, choose the chapter you need, and I will choose "the era of understanding" here.