The electronic textbook of primary school mathematics is an image file, which should be processed by image editing software.

1. "Drawing" cut in.

Copy and paste the picture into the Drawing. Use the selection toolbox in the drawing to select the desired copy of the content. In "Drawing"-New-Paste, save the pasted contents-save to the desktop (easy to find). The saving format is preferably jpg format.

2. Use ACDSee 5.0 software.

Right-click "Picture of Primary Mathematics Electronic Textbook"-select ACDSee 5.0 as the opening mode. Click the editor that comes with it, and check the box to delete the unwanted content. Click File-Save.

There are also many picture editing software that can cut pictures. These two softwares are the most commonly used and easy to operate.