A simply way to apply number formatting is to use shortcut keys.
This tip summarizes the shortcut-key combinations that you can use to apply common number formatting to the selected cells or range.

Often, data imported into an Excel worksheet contains excess spaces or strange (often unprintable) characters. There are two handy functions TRIM and CLEAN to cleanup such data.

Sometimes it is handy to view (and print) the formulas in all the cells in a spreadsheet without having to enter each cell manually.

If you have lengthy text in a cell, you can force Excel to display it in multiple lines within the cell.