Office Libre Strikethrough

How to add a Strikethrough button to your toolbar:

In LibreOffice go to Tools -> Customize… -> Toolbars

1. Toolbar: Select "Formatting"
2. Commands: scroll down to "Underline" and highlight it
3. Click the "Add…" button
4. Category: select "Format"
5. Commands: scroll down and select "Strikethrough"
6. Click the Add button

You now have a strikethrough button available in your Formatting toolbar.