A lot of times we have to apply the same formula for a range of cells. 
Normally, we put it in one cell and then copy and paste the formula in all the other cells.

How to:
1. Select the data range in which you wish to enter the formula. You will notice that the first cell is lighter in color when compared to the other selected cells. It’s the active cell.
2. Start typing the formula (or text) that you want in all the cells in the active cell. 
3. Use Control + Enter instead of Enter (Keep Control key pressed when you hit Enter).