LibreOffice Calc allows you to format cells in any type without changing its value. You can change a value “0.5” to “50%” or “$0.5”, or change the appearance of the cell itself.
Format Cells in Calc
Type any number in any cell of Calc.
By default, Calc uses default number format when you type a number in a cell. To format the number, right-click on the cell and select “Format Cells”.
On the Format Cells dialog, choose the category as Currency, Format as USD $ (Or anything you want), select desired formatting in the format list. You can also choose a number of decimal places, leading zeros you want. Once you are satisfied by looking at the preview, press OK.
To change the above number to %, you can click the % icon in the toolbar after selecting the cell. Calc provides common number formats in the toolbar itself for easy access.
Use Borders, border style, Font Color and alignment from the toolbar to give the cell a different look:
Once it is applied to the cell, it would look like this:
Is there any way to set it as default for the whole sheet?
You need to select the entire sheet and then apply them.