Strikethrough is to mark the contents that you want to remove, which makes your work looks better. Please also refer to the shortcut Ctrl+5. Please follow the steps below for details:
Step 1: Select the cell or area you need to change;
Step 2: Right click your mouse to bring up the dialog box, from the list, click "Format cells";
Step 3: In the "Format Cells" dialog box, check "Strikethrough";
Step 4: Click "OK" at the bottom.